Allow Serial Overrun Protection to be disabled

Marlin/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/default/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/AlephObjects/TAZ4/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/Anet/A2/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/Anet/A2plus/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/Anet/A6/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/Anet/A8/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/ArmEd/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/BIBO/TouchX/cyclops/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/BIBO/TouchX/default/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/BQ/Hephestos/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/BQ/Hephestos_2/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 #define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/BQ/WITBOX/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/Cartesio/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/Creality/CR-10/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/Creality/CR-10S/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 #define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/Creality/CR-10mini/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/Creality/CR-8/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/Creality/Ender-2/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/Creality/Ender-3/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/Creality/Ender-4/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/Einstart-S/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/Felix/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/FolgerTech/i3-2020/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/Formbot/Raptor/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 #define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/Formbot/T_Rex_2+/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/Formbot/T_Rex_3/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/Geeetech/MeCreator2/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/Geeetech/Prusa i3 Pro C/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/Geeetech/Prusa i3 Pro W/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/Infitary/i3-M508/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/JGAurora/A5/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/MakerParts/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/Malyan/M150/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/Malyan/M200/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/Micromake/C1/enhanced/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/Mks/Sbase/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/RigidBot/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/SCARA/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/Sanguinololu/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/TheBorg/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/TinyBoy2/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/Tronxy/X3A/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/UltiMachine/Archim1/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/UltiMachine/Archim2/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/Velleman/K8200/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/Velleman/K8400/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/Wanhao/Duplicator 6/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/delta/Anycubic/Kossel/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/delta/FLSUN/auto_calibrate/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/delta/FLSUN/kossel/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/delta/FLSUN/kossel_mini/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/delta/Geeetech/Rostock 301/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/delta/Tevo Little Monster/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/delta/generic/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/delta/kossel_mini/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/delta/kossel_xl/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/gCreate/gMax1.5+/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/makibox/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/tvrrug/Round2/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/config/examples/wt150/Configuration_adv.h

 // Some clients will have this feature soon. This could make the NO_TIMEOUTS unnecessary.
 //#define ADVANCED_OK
 
+// Printrun may have trouble receiving long strings all at once.
+// This option inserts short delays between lines of serial output.
+#define SERIAL_OVERRUN_PROTECTION
+
 // @section extras
 
 /**

Marlin/src/core/utility.h

 
 constexpr char axis_codes[XYZE] = { 'X', 'Y', 'Z', 'E' };
 
+// Delay that ensures heaters and watchdog are kept alive
 void safe_delay(millis_t ms);
 
+// A delay to provide brittle hosts time to receive bytes
+inline void serial_delay(const millis_t ms) {
+  #if ENABLED(SERIAL_OVERRUN_PROTECTION)
+    safe_delay(ms);
+  #else
+    UNUSED(ms);
+  #endif
+}
+
 #if ENABLED(EEPROM_SETTINGS) || ENABLED(SD_FIRMWARE_UPDATE)
   void crc16(uint16_t *crc, const void * const data, uint16_t cnt);
 #endif

Marlin/src/feature/bedlevel/ubl/ubl.cpp

           SERIAL_ECHOPGM_P(port, " Z");
           SERIAL_ECHO_F_P(port, z_values[x][y], 2);
           SERIAL_EOL_P(port);
-          safe_delay(75); // Prevent Printrun from exploding
+          serial_delay(75); // Prevent Printrun from exploding
         }
   }
 
     SERIAL_PROTOCOLPGM_P(port, " System v" UBL_VERSION " ");
     if (!planner.leveling_active) SERIAL_PROTOCOLPGM_P(port, "in");
     SERIAL_PROTOCOLLNPGM_P(port, "active.");
-    safe_delay(50);
+    serial_delay(50);
   }
 
   #if ENABLED(UBL_DEVEL_DEBUGGING)
     if (y < 100) { SERIAL_CHAR(' '); if (y < 10) SERIAL_CHAR(' '); }
     SERIAL_ECHO(y);
     SERIAL_CHAR(')');
-    safe_delay(5);
+    serial_delay(5);
   }
 
   static void serial_echo_column_labels(const uint8_t sp) {
       SERIAL_ECHO(i);
       SERIAL_ECHO_SP(sp);
     }
-    safe_delay(10);
+    serial_delay(10);
   }
 
   /**

Marlin/src/feature/bedlevel/ubl/ubl_G29.cpp

           }
         }
       }
-      safe_delay(15);
+      serial_delay(15);
       return false;
     }
 
           SERIAL_FLUSH();                                           // Prevent host M105 buffer overrun.
         } while (!ui.button_pressed());
 
-        if (!lcd_map_control) ui.return_to_status();               // Just editing a single point? Return to status
+        if (!lcd_map_control) ui.return_to_status();                // Just editing a single point? Return to status
 
         if (click_and_hold(abort_fine_tune)) goto FINE_TUNE_EXIT;   // If the click is held down, abort editing
 
         z_values[location.x_index][location.y_index] = new_z;       // Save the updated Z value
 
-        safe_delay(20);                                             // No switch noise
+        serial_delay(20);                                           // No switch noise
         ui.refresh();
 
       } while (location.x_index >= 0 && --g29_repetition_cnt > 0);
               SERIAL_PROTOCOLCHAR(',');
               SERIAL_PROTOCOL_F(z_tmp, 7);
               SERIAL_ECHOPGM("]   ---> ");
-              safe_delay(20);
+              serial_delay(20);
             }
           #endif
 
               SERIAL_PROTOCOLCHAR(',');
               SERIAL_PROTOCOL_F(z_tmp, 7);
               SERIAL_ECHOLNPGM("]");
-              safe_delay(55);
+              serial_delay(55);
             }
           #endif
 
           SERIAL_ECHOPGM("  D=");
           SERIAL_PROTOCOL_F(lsf_results.D, 7);
           SERIAL_EOL();
-          safe_delay(55);
+          serial_delay(55);
 
           SERIAL_ECHOPGM("bed plane normal = [");
           SERIAL_PROTOCOL_F(normal.x, 7);
         SERIAL_PROTOCOLPGM(" Loaded.");
       }
       SERIAL_EOL();
-      safe_delay(50);
+      serial_delay(50);
 
       #if ENABLED(ENABLE_LEVELING_FADE_HEIGHT)
         SERIAL_PROTOCOLPGM("planner.z_fade_height : ");
         SERIAL_EOL();
       #endif
 
-      SERIAL_ECHOLNPAIR("MESH_MIN_X  " STRINGIFY(MESH_MIN_X) "=", MESH_MIN_X); safe_delay(50);
-      SERIAL_ECHOLNPAIR("MESH_MIN_Y  " STRINGIFY(MESH_MIN_Y) "=", MESH_MIN_Y); safe_delay(50);
-      SERIAL_ECHOLNPAIR("MESH_MAX_X  " STRINGIFY(MESH_MAX_X) "=", MESH_MAX_X); safe_delay(50);
-      SERIAL_ECHOLNPAIR("MESH_MAX_Y  " STRINGIFY(MESH_MAX_Y) "=", MESH_MAX_Y); safe_delay(50);
-      SERIAL_ECHOLNPAIR("GRID_MAX_POINTS_X  ", GRID_MAX_POINTS_X);             safe_delay(50);
-      SERIAL_ECHOLNPAIR("GRID_MAX_POINTS_Y  ", GRID_MAX_POINTS_Y);             safe_delay(50);
+      SERIAL_ECHOLNPAIR("MESH_MIN_X  " STRINGIFY(MESH_MIN_X) "=", MESH_MIN_X); serial_delay(50);
+      SERIAL_ECHOLNPAIR("MESH_MIN_Y  " STRINGIFY(MESH_MIN_Y) "=", MESH_MIN_Y); serial_delay(50);
+      SERIAL_ECHOLNPAIR("MESH_MAX_X  " STRINGIFY(MESH_MAX_X) "=", MESH_MAX_X); serial_delay(50);
+      SERIAL_ECHOLNPAIR("MESH_MAX_Y  " STRINGIFY(MESH_MAX_Y) "=", MESH_MAX_Y); serial_delay(50);
+      SERIAL_ECHOLNPAIR("GRID_MAX_POINTS_X  ", GRID_MAX_POINTS_X);             serial_delay(50);
+      SERIAL_ECHOLNPAIR("GRID_MAX_POINTS_Y  ", GRID_MAX_POINTS_Y);             serial_delay(50);
       SERIAL_ECHOLNPAIR("MESH_X_DIST  ", MESH_X_DIST);
-      SERIAL_ECHOLNPAIR("MESH_Y_DIST  ", MESH_Y_DIST);                         safe_delay(50);
+      SERIAL_ECHOLNPAIR("MESH_Y_DIST  ", MESH_Y_DIST);                         serial_delay(50);
 
       SERIAL_PROTOCOLPGM("X-Axis Mesh Points at: ");
       for (uint8_t i = 0; i < GRID_MAX_POINTS_X; i++) {
         SERIAL_PROTOCOL_F(LOGICAL_X_POSITION(mesh_index_to_xpos(i)), 3);
         SERIAL_PROTOCOLPGM("  ");
-        safe_delay(25);
+        serial_delay(25);
       }
       SERIAL_EOL();
 
       for (uint8_t i = 0; i < GRID_MAX_POINTS_Y; i++) {
         SERIAL_PROTOCOL_F(LOGICAL_Y_POSITION(mesh_index_to_ypos(i)), 3);
         SERIAL_PROTOCOLPGM("  ");
-        safe_delay(25);
+        serial_delay(25);
       }
       SERIAL_EOL();
 
         SERIAL_PROTOCOLLNPAIR("  state:", READ(KILL_PIN));
       #endif
       SERIAL_EOL();
-      safe_delay(50);
+      serial_delay(50);
 
       #if ENABLED(UBL_DEVEL_DEBUGGING)
         SERIAL_PROTOCOLLNPAIR("ubl_state_at_invocation :", ubl_state_at_invocation); SERIAL_EOL();
         SERIAL_PROTOCOLLNPAIR("ubl_state_recursion_chk :", ubl_state_recursion_chk); SERIAL_EOL();
-        safe_delay(50);
+        serial_delay(50);
 
         SERIAL_PROTOCOLPAIR("Meshes go from ", hex_address((void*)settings.meshes_start_index()));
         SERIAL_PROTOCOLLNPAIR(" to ", hex_address((void*)settings.meshes_end_index()));
-        safe_delay(50);
+        serial_delay(50);
 
         SERIAL_PROTOCOLLNPAIR("sizeof(ubl) :  ", (int)sizeof(ubl));         SERIAL_EOL();
         SERIAL_PROTOCOLLNPAIR("z_value[][] size: ", (int)sizeof(z_values)); SERIAL_EOL();
-        safe_delay(25);
+        serial_delay(25);
 
         SERIAL_PROTOCOLLNPAIR("EEPROM free for UBL: ", hex_address((void*)(settings.meshes_end_index() - settings.meshes_start_index())));
-        safe_delay(50);
+        serial_delay(50);
 
         SERIAL_PROTOCOLPAIR("EEPROM can hold ", settings.calc_num_meshes());
         SERIAL_PROTOCOLLNPGM(" meshes.\n");
-        safe_delay(25);
+        serial_delay(25);
       #endif // UBL_DEVEL_DEBUGGING
 
       if (!sanity_check()) {

Marlin/src/gcode/calibrate/M100.cpp

         print_hex_byte(ptr[i]);
         SERIAL_CHAR(' ');
       }
-      safe_delay(25);
+      serial_delay(25);
       SERIAL_CHAR('|');                   // Point out non test bytes
       for (uint8_t i = 0; i < 16; i++) {
         char ccc = (char)ptr[i]; // cast to char before automatically casting to char on assignment, in case the compiler is broken
       }
       SERIAL_EOL();
       ptr += 16;
-      safe_delay(25);
+      serial_delay(25);
       idle();
     }
   }
     // safe_delay(20);                 // boards.
     // while ( !READ(63))
     //   idle();
-    safe_delay(20);
+    serial_delay(20);
     #if ENABLED(M100_FREE_MEMORY_DUMPER)
       M100_dump_routine(PSTR("   Memory corruption detected with sp<Heap\n"), (char*)0x1B80, (char*)0x21FF);
     #endif