Define max_e_jerk as array always

Marlin/src/module/planner.cpp

 
 uint32_t Planner::max_acceleration_steps_per_s2[XYZE_N]; // (steps/s^2) Derived from mm_per_s2
 
-float Planner::steps_to_mm[XYZE_N];           // (mm) Millimeters per step
+float Planner::steps_to_mm[XYZE_N];             // (mm) Millimeters per step
 
 #if HAS_JUNCTION_DEVIATION
-  float Planner::junction_deviation_mm;       // (mm) M205 J
+  float Planner::junction_deviation_mm;         // (mm) M205 J
   #if ENABLED(LIN_ADVANCE)
-    float Planner::max_e_jerk               // Calculated from junction_deviation_mm
+    float Planner::max_e_jerk                   // Calculated from junction_deviation_mm
-      TERN_(DISTINCT_E_FACTORS, [EXTRUDERS]);
+      [TERN(DISTINCT_E_FACTORS, EXTRUDERS, 1)];
   #endif
 #endif
 
 
     #if ENABLED(LIN_ADVANCE)
 
-      #if HAS_JUNCTION_DEVIATION
+      #define MAX_E_JERK(N) TERN(HAS_JUNCTION_DEVIATION, max_e_jerk[E_AXIS_N(N)], max_jerk.e)
-        #if ENABLED(DISTINCT_E_FACTORS)
-          #define MAX_E_JERK max_e_jerk[extruder]
-        #else
-          #define MAX_E_JERK max_e_jerk
-        #endif
-      #else
-        #define MAX_E_JERK max_jerk.e
-      #endif
 
       /**
        *
         if (block->e_D_ratio > 3.0f)
           block->use_advance_lead = false;
         else {
-          const uint32_t max_accel_steps_per_s2 = MAX_E_JERK / (extruder_advance_K[active_extruder] * block->e_D_ratio) * steps_per_mm;
+          const uint32_t max_accel_steps_per_s2 = MAX_E_JERK(extruder) / (extruder_advance_K[active_extruder] * block->e_D_ratio) * steps_per_mm;
           if (TERN0(LA_DEBUG, accel > max_accel_steps_per_s2))
             SERIAL_ECHOLNPGM("Acceleration limited.");
           NOMORE(accel, max_accel_steps_per_s2);

Marlin/src/module/planner.h

       static float junction_deviation_mm;       // (mm) M205 J
       #if ENABLED(LIN_ADVANCE)
         static float max_e_jerk                 // Calculated from junction_deviation_mm
-          TERN_(DISTINCT_E_FACTORS, [EXTRUDERS]);
+          [TERN(DISTINCT_E_FACTORS, EXTRUDERS, 1)];
       #endif
     #endif
 
 
     #if HAS_LINEAR_E_JERK
       FORCE_INLINE static void recalculate_max_e_jerk() {
-        #define GET_MAX_E_JERK(N) SQRT(junction_deviation_mm * (N) * SQRT(0.5) / (1.0f - SQRT(0.5)))
+        const float prop = junction_deviation_mm * SQRT(0.5) / (1.0f - SQRT(0.5));
-        #if ENABLED(DISTINCT_E_FACTORS)
+        LOOP_L_N(i, EXTRUDERS)
-          LOOP_L_N(i, EXTRUDERS)
+          max_e_jerk[E_AXIS_N(i)] = SQRT(prop * settings.max_acceleration_mm_per_s2[E_AXIS_N(i)]);
-            max_e_jerk[i] = GET_MAX_E_JERK(settings.max_acceleration_mm_per_s2[E_AXIS_N(i)]);
-        #else
-          max_e_jerk = GET_MAX_E_JERK(settings.max_acceleration_mm_per_s2[E_AXIS]);
-        #endif
       }
     #endif