Define Z_MIN_PROBE_PIN always, allowing override

Marlin/pins_AZTEEG_X3_PRO.h

   #define Z_MAX_PIN        18
 #endif
 
-
-#if ENABLED(Z_MIN_PROBE_ENDSTOP)
-  //#undef Z_MIN_PIN
-  //#define Z_MIN_PIN        15
-  // Define a pin to use as the signal pin on Arduino for the Z probe endstop.
+#ifndef Z_MIN_PROBE_PIN
   #define Z_MIN_PROBE_PIN  19
 #endif
-//
+
 #define E2_STEP_PIN        23
 #define E2_DIR_PIN         25
 #define E2_ENABLE_PIN      40

Marlin/pins_BRAINWAVE_PRO.h

 
 #define LARGE_FLASH        true
 
+#define X_STOP_PIN         47
+#define Y_STOP_PIN         18
+#define Z_MAX_PIN          36
+#ifndef Z_MIN_PROBE_PIN
+  #define Z_MIN_PROBE_PIN  17
+#endif
+
 #define X_STEP_PIN         33
 #define X_DIR_PIN          32
 #define X_ENABLE_PIN       11
-#define X_STOP_PIN         47
 
 #define Y_STEP_PIN         31
 #define Y_DIR_PIN          30
 #define Y_ENABLE_PIN        8
-#define Y_STOP_PIN         18
 
 #define Z_STEP_PIN         29
 #define Z_DIR_PIN          28
 #define Z_ENABLE_PIN       37
-#define Z_MAX_PIN          36
-#define Z_MIN_PROBE_PIN    17  // Bed Z probe
 
 #define E0_STEP_PIN        35
 #define E0_DIR_PIN         34

Marlin/pins_RAMBO.h

   #define SLED_PIN         -1
 #endif
 
-#define X_STEP_PIN 37
-#define X_DIR_PIN 48
 #define X_MIN_PIN 12
 #define X_MAX_PIN 24
+#define Y_MIN_PIN 11
+#define Y_MAX_PIN 23
+#define Z_MIN_PIN 10
+#define Z_MAX_PIN 30
+#ifndef Z_MIN_PROBE_PIN
+  #define Z_MIN_PROBE_PIN 10
+#endif
+
+#define X_STEP_PIN 37
+#define X_DIR_PIN 48
 #define X_ENABLE_PIN 29
 #define X_MS1_PIN 40
 #define X_MS2_PIN 41
 
 #define Y_STEP_PIN 36
 #define Y_DIR_PIN 49
-#define Y_MIN_PIN 11
-#define Y_MAX_PIN 23
 #define Y_ENABLE_PIN 28
 #define Y_MS1_PIN 69
 #define Y_MS2_PIN 39
 
 #define Z_STEP_PIN 35
 #define Z_DIR_PIN 47
-#define Z_MIN_PIN 10
-#define Z_MAX_PIN 30
 #define Z_ENABLE_PIN 27
 #define Z_MS1_PIN 68
 #define Z_MS2_PIN 67

Marlin/pins_RAMPS.h

 #define SERVO2_PIN          5
 #define SERVO3_PIN          4
 
-#define X_STEP_PIN         54
-#define X_DIR_PIN          55
-#define X_ENABLE_PIN       38
 #define X_MIN_PIN           3
 #ifndef X_MAX_PIN
   #define X_MAX_PIN         2
 #endif
+#define Y_MIN_PIN          14
+#define Y_MAX_PIN          15
+#define Z_MIN_PIN          18
+#define Z_MAX_PIN          19
+#ifndef Z_MIN_PROBE_PIN
+  #define Z_MIN_PROBE_PIN  32
+#endif
+
+#define X_STEP_PIN         54
+#define X_DIR_PIN          55
+#define X_ENABLE_PIN       38
 
 #define Y_STEP_PIN         60
 #define Y_DIR_PIN          61
 #define Y_ENABLE_PIN       56
-#define Y_MIN_PIN          14
-#define Y_MAX_PIN          15
 
 #define Z_STEP_PIN         46
 #define Z_DIR_PIN          48
 #define Z_ENABLE_PIN       62
-#define Z_MIN_PIN          18
-#define Z_MAX_PIN          19
 
 #define E0_STEP_PIN        26
 #define E0_DIR_PIN         28
 // Use the RAMPS 1.4 Analog input 5 on the AUX2 connector
 #define FILWIDTH_PIN        5 // ANALOG NUMBERING
 
-#if ENABLED(Z_MIN_PROBE_ENDSTOP)
-  // Define a pin to use as the signal pin on Arduino for the Z_PROBE endstop.
-  #define Z_MIN_PROBE_PIN  32
-#endif
-
 // define digital pin 4 for the filament runout sensor. Use the RAMPS 1.4 digital input 4 on the servos connector
 #define FIL_RUNOUT_PIN      4
 

Marlin/pins_RIGIDBOARD.h

  * RIGIDBOARD Arduino Mega with RAMPS v1.4 pin assignments
  */
 
-#include "pins_RAMPS.h"
-
-#undef BOARD_NAME
 #define BOARD_NAME "RigidBoard"
 
-#if ENABLED(Z_MIN_PROBE_ENDSTOP)
-  #undef Z_MAX_PIN
-  #define Z_MAX_PIN -1
-  #undef Z_MIN_PROBE_PIN
+#define RAMPS_D10_PIN       9    // EXTRUDER 1
+#define MOSFET_D_PIN       12    // EXTRUDER 2 or FAN
+#ifndef Z_MIN_PROBE_PIN
   #define Z_MIN_PROBE_PIN  19    // Z-MAX pin J14 End Stops
 #endif
 
-#undef HEATER_0_PIN
-#undef HEATER_1_PIN
-#define HEATER_0_PIN        9    // EXTRUDER 1
-#define HEATER_1_PIN       12    // EXTRUDER 2 (FAN On Sprinter)
+#include "pins_RAMPS.h"
 
 #undef TEMP_0_PIN
 #undef TEMP_1_PIN

Marlin/pins_RUMBA.h

 #define Z_MIN_PIN          33
 #define Z_MAX_PIN          32
 
-#if ENABLED(Z_MIN_PROBE_ENDSTOP)
-  // Define a pin to use as the signal pin on Arduino for the Z probe endstop.
+#ifndef Z_MIN_PROBE_PIN
   #define Z_MIN_PROBE_PIN  33
 #endif