thinkyhead · pull · Jan 23, 2026 · Jan 23, 2026 · Jan 23, 2026 · Jan 23, 2026
diff --git a/Marlin/Version.h b/Marlin/Version.h
@@ -41,7 +41,7 @@
  * here we define this default string as the date where the latest release
  * version was tagged.
  */
-//#define STRING_DISTRIBUTION_DATE "2026-01-22"
+//#define STRING_DISTRIBUTION_DATE "2026-01-23"
 
 /**
  * The protocol for communication to the host. Protocol indicates communication

diff --git a/Marlin/src/inc/SanityCheck.h b/Marlin/src/inc/SanityCheck.h
@@ -870,8 +870,8 @@ static_assert(COUNT(arm) == LOGICAL_AXES, "AXIS_RELATIVE_MODES must contain " _L
 #if ENABLED(NONLINEAR_EXTRUSION)
   #if HAS_MULTI_EXTRUDER
     #error "NONLINEAR_EXTRUSION doesn't currently support multi-extruder setups."
-  #elif DISABLED(CPU_32_BIT)
-    #error "NONLINEAR_EXTRUSION requires a 32-bit CPU."
+  #elif NONE(CPU_32_BIT, NO_STANDARD_MOTION)
+    #error "NONLINEAR_EXTRUSION requires a 32-bit CPU or NO_STANDARD_MOTION."
   #endif
 #endif
 
@@ -2715,6 +2715,22 @@ static_assert(NUM_SERVOS <= NUM_SERVO_PLUGS, "NUM_SERVOS (or some servo index) i
   #elif ENABLED(NEO2_COLOR_PRESETS) && DISABLED(NEOPIXEL2_SEPARATE)
     #error "NEO2_COLOR_PRESETS requires NEOPIXEL2_SEPARATE to be enabled."
   #endif
+  #ifdef BOARD_NEOPIXEL_MAX
+    #if (NEOPIXEL_PIXELS > BOARD_NEOPIXEL_MAX && NEOPIXEL_PIN == BOARD_NEOPIXEL_PIN) || (NEOPIXEL_PIXELS > BOARD_NEOPIXEL_MAX && DISABLED(NEOPIXEL2_SEPARATE) && NEOPIXEL2_PIN == BOARD_NEOPIXEL_PIN)
+      #if ENABLED(BOARD_HAS_DCDC5V)
+        #error "NEOPIXEL_PIXELS exceeds the recommended maximum for your MOTHERBOARD."
+      #elif MB(BTT_SKR_MINI_E3_V2_0, BTT_SKR_MINI_E3_V3_0)
+        static_assert(false, "\nNEOPIXEL_PIXELS exceeds the recommended maximum for your MOTHERBOARD.\nConsider adding a 5V DC-DC converter and #define BOARD_HAS_DCDC5V to your Configuration.h.");
+      #endif
+    #endif
+    #if ENABLED(NEOPIXEL2_SEPARATE) && NEOPIXEL2_PIXELS > BOARD_NEOPIXEL_MAX && NEOPIXEL2_PIN == BOARD_NEOPIXEL_PIN
+      #if ENABLED(BOARD_HAS_DCDC5V)
+        #error "NEOPIXEL2_PIXELS exceeds the recommended maximum for your MOTHERBOARD."
+      #elif MB(BTT_SKR_MINI_E3_V2_0, BTT_SKR_MINI_E3_V3_0)
+        static_assert(false, "\nNEOPIXEL2_PIXELS exceeds the recommended maximum for your MOTHERBOARD.\nConsider adding a 5V DC-DC converter and #define BOARD_HAS_DCDC5V to your Configuration.h.");
+      #endif
+    #endif
+  #endif
 #endif
 
 #if DISABLED(NO_COMPILE_TIME_PWM)
@@ -4499,9 +4515,7 @@ static_assert(_PLUS_TEST(3), "DEFAULT_MAX_ACCELERATION values must be positive."
     #error "EMERGENCY_PARSER is required with FTM_RESONANCE_TEST (to cancel the test)."
   #endif
   #if !HAS_STANDARD_MOTION
-    #if ENABLED(NONLINEAR_EXTRUSION)
-      #error "NONLINEAR_EXTRUSION is not yet available in FT_MOTION. Disable NO_STANDARD_MOTION if you require it."
-    #elif ENABLED(SMOOTH_LIN_ADVANCE)
+    #if ENABLED(SMOOTH_LIN_ADVANCE)
       #error "SMOOTH_LIN_ADVANCE is not yet available in FT_MOTION. Disable NO_STANDARD_MOTION if you require it."
     #elif ENABLED(MIXING_EXTRUDER)
       #error "MIXING_EXTRUDER is not yet available in FT_MOTION. Disable NO_STANDARD_MOTION if you require it."

diff --git a/Marlin/src/inc/Version.h b/Marlin/src/inc/Version.h
@@ -42,7 +42,7 @@
  * version was tagged.
  */
 #ifndef STRING_DISTRIBUTION_DATE
-  #define STRING_DISTRIBUTION_DATE "2026-01-22"
+  #define STRING_DISTRIBUTION_DATE "2026-01-23"
 #endif
 
 /**

diff --git a/Marlin/src/inc/Warnings.cpp b/Marlin/src/inc/Warnings.cpp
@@ -941,9 +941,6 @@
   #if ENABLED(I2S_STEPPER_STREAM)
     #warning "FT_MOTION has not been tested with I2S_STEPPER_STREAM."
   #endif
-  #if ENABLED(NONLINEAR_EXTRUSION)
-    #warning "NONLINEAR_EXTRUSION does not (currently) operate when FT_MOTION is the active motion system."
-  #endif
   #if ENABLED(LIN_ADVANCE)
     #warning "Be aware that FT_MOTION K factor is now set with M900 K (same as LIN_ADVANCE)."
     #if DISABLED(FTM_SMOOTHING)

diff --git a/Marlin/src/lcd/extui/dgus_e3s1pro/dgus_e3s1pro_extui.cpp b/Marlin/src/lcd/extui/dgus_e3s1pro/dgus_e3s1pro_extui.cpp
@@ -203,4 +203,4 @@ namespace ExtUI {
   void onAxisEnabled(const axis_t) {}
 }
 
-#endif // DGUS_LCD_UI_RELOADED
+#endif // DGUS_LCD_UI_E3S1PRO
diff --git a/Marlin/src/lcd/menu/menu_mmu2.cpp b/Marlin/src/lcd/menu/menu_mmu2.cpp
@@ -43,15 +43,15 @@ inline void action_mmu2_load_to_nozzle(const uint8_t tool) {
   ui.reset_status();
   ui.return_to_status();
   ui.status_printf(0, GET_TEXT_F(MSG_MMU2_LOADING_FILAMENT), int(tool + 1));
-  TERN(HAS_PRUSA_MMU3, mmu3.load_to_nozzle(tool), mmu2.load_to_nozzle(tool));
+  TERN(HAS_PRUSA_MMU3, mmu3, mmu2).load_to_nozzle(tool);
   ui.reset_status();
 }
 
 void _mmu2_load_to_feeder(const uint8_t tool) {
   ui.reset_status();
   ui.return_to_status();
   ui.status_printf(0, GET_TEXT_F(MSG_MMU2_LOADING_FILAMENT), int(tool + 1));
-  TERN(HAS_PRUSA_MMU3, mmu3.load_to_feeder(tool), mmu2.load_to_feeder(tool));
+  TERN(HAS_PRUSA_MMU3, mmu3, mmu2).load_to_feeder(tool);
   ui.reset_status();
 }
 
@@ -82,7 +82,8 @@ void _mmu2_eject_filament(uint8_t index) {
   ui.reset_status();
   ui.return_to_status();
   ui.status_printf(0, GET_TEXT_F(MSG_MMU2_EJECTING_FILAMENT), int(index + 1));
-  if (mmu3.eject_filament(index, true)) ui.reset_status();
+  if (TERN(HAS_PRUSA_MMU3, mmu3, mmu2).eject_filament(index, true))
+    ui.reset_status();
 }
 
 void _mmu2_cut_filament(uint8_t index) {
@@ -97,7 +98,7 @@ void action_mmu2_unload_filament() {
   ui.reset_status();
   ui.return_to_status();
   LCD_MESSAGE(MSG_MMU2_UNLOADING_FILAMENT);
-  while (!TERN(HAS_PRUSA_MMU3, mmu3.unload(), mmu2.unload())) {
+  while (!TERN(HAS_PRUSA_MMU3, mmu3, mmu2).unload()) {
     safe_delay(50);
     TERN(HAS_PRUSA_MMU3, MMU3::marlin_idle(true), marlin.idle());
   }
@@ -342,7 +343,7 @@ void menu_mmu2_choose_filament() {
 //
 
 void menu_mmu2_pause() {
-  feeder_index = mmu3.get_current_tool();
+  feeder_index = TERN(HAS_PRUSA_MMU3, mmu3, mmu2).get_current_tool();
   START_MENU();
   #if LCD_HEIGHT > 2
     STATIC_ITEM(MSG_FILAMENT_CHANGE_HEADER, SS_DEFAULT|SS_INVERT);

diff --git a/Marlin/src/module/ft_motion.cpp b/Marlin/src/module/ft_motion.cpp
@@ -478,21 +478,42 @@ xyze_float_t FTMotion::calc_traj_point(const float dist) {
   LOGICAL_AXIS_MAP_LC(_SET_TRAJ);
 
   #if FTM_HAS_LIN_ADVANCE
-    const float advK = planner.get_advance_k();
-    if (advK) {
-      const float traj_e = traj_coords.e;
-      if (use_advance_lead) {
-        // Don't apply LA to retract/unretract blocks
-        const float e_rate = (traj_e - prev_traj_e) * (FTM_FS);
+
+    // Apply LA/NLE only to printing (not retract/unretract) blocks
+
+    if (use_advance_lead) {
+      const float advK = planner.get_advance_k();
+      if (advK || TERN0(NONLINEAR_EXTRUSION, stepper.ne.settings.enabled)) {
+        float traj_e = traj_coords.e;
+        const float traj_e_delta = traj_e - prev_traj_e; // extruder delta in mm, always positive for use_advance_lead (printing moves)
+        const float e_rate = traj_e_delta * FTM_FS;      // extruder velocity in mm/s
+
         traj_coords.e += e_rate * advK;
+
+        #if ENABLED(NONLINEAR_EXTRUSION)
+          if (stepper.ne.settings.enabled) {
+            const nonlinear_coeff_t &coeff = stepper.ne.settings.coeff;
+            const float multiplier = max(coeff.C, coeff.A * sq(e_rate) + coeff.B * e_rate + coeff.C),
+                        nle_term = traj_e_delta * (multiplier - 1);
+
+            traj_coords.e += nle_term;
+            traj_e += nle_term;
+            startPos.e += nle_term;
+            endPos_prevBlock.e += nle_term;
+          }
+        #endif
+
+        prev_traj_e = traj_e;
       }
-      prev_traj_e = traj_e;
     }
-  #endif
+
+  #endif // FTM_HAS_LIN_ADVANCE
 
   // Update shaping parameters if needed.
   switch (cfg.dynFreqMode) {
+
     #if HAS_DYNAMIC_FREQ_MM
+
       case dynFreqMode_Z_BASED: {
         static float oldz = 0.0f;
         const float z = traj_coords.z;
@@ -509,9 +530,11 @@ xyze_float_t FTMotion::calc_traj_point(const float dist) {
           shaping.refresh_largest_delay_samples();
         }
       } break;
+
     #endif
 
     #if HAS_DYNAMIC_FREQ_G
+
       case dynFreqMode_MASS_BASED:
         // Update constantly. The optimization done for Z value makes
         // less sense for E, as E is expected to constantly change.
@@ -523,6 +546,7 @@ xyze_float_t FTMotion::calc_traj_point(const float dist) {
         #endif
         shaping.refresh_largest_delay_samples();
         break;
+
     #endif
 
     default: break;

diff --git a/Marlin/src/module/stepper.h b/Marlin/src/module/stepper.h
@@ -292,12 +292,14 @@ constexpr ena_mask_t enable_overlap[] = {
     #define NONLINEAR_EXTRUSION_Q24 1
   #endif
 
+  typedef struct {
+    float A, B, C;
+    void reset() { A = B = 0.0f; C = 1.0f; }
+  } nonlinear_coeff_t;
+
   typedef struct {
     bool enabled;
-    struct {
-      float A, B, C;
-      void reset() { A = B = 0.0f; C = 1.0f; }
-    } coeff;
+    nonlinear_coeff_t coeff;
     void reset() {
       enabled = ENABLED(NONLINEAR_EXTRUSION_DEFAULT_ON);
       coeff.reset();

diff --git a/Marlin/src/pins/stm32f1/pins_BTT_SKR_MINI_E3_V2_0.h b/Marlin/src/pins/stm32f1/pins_BTT_SKR_MINI_E3_V2_0.h
@@ -69,8 +69,11 @@
 // Release PA13/PA14 (led, usb control) from SWD pins
 #define DISABLE_DEBUG
 
-#ifndef BOARD_NEOPIXEL_PIN
-  #define BOARD_NEOPIXEL_PIN                PA8   // LED driving pin
+#define BOARD_NEOPIXEL_PIN                  PA8   // LED driving pin
+#ifndef BOARD_HAS_DCDC5V
+  #define BOARD_NEOPIXEL_MAX                  7   // Max number of NEOPIXELS supported on this board
+#else
+  #define BOARD_NEOPIXEL_MAX                 29   // With 5V DC-DC converter
 #endif
 
 #ifndef PS_ON_PIN

diff --git a/Marlin/src/pins/stm32g0/pins_BTT_SKR_MINI_E3_V3_0.h b/Marlin/src/pins/stm32g0/pins_BTT_SKR_MINI_E3_V3_0.h
@@ -453,8 +453,11 @@
 //
 // NeoPixel
 //
-#ifndef BOARD_NEOPIXEL_PIN
-  #define BOARD_NEOPIXEL_PIN                PA8   // LED driving pin
+#define BOARD_NEOPIXEL_PIN                  PA8   // LED driving pin
+#ifndef BOARD_HAS_DCDC5V
+  #define BOARD_NEOPIXEL_MAX                  7   // Max number of NEOPIXELS supported on this board
+#else
+  #define BOARD_NEOPIXEL_MAX                 29   // With 5V DC-DC converter
 #endif
 
 // Pins for documentation and sanity checks only.