diff --git a/Marlin/Marlin_main.cpp b/Marlin/Marlin_main.cpp
index 5a073145a7..9be4fd9b1a 100755
--- a/Marlin/Marlin_main.cpp
+++ b/Marlin/Marlin_main.cpp
@@ -6892,8 +6892,7 @@ inline void gcode_M503() {
     KEEPALIVE_STATE(IN_HANDLER);
 
     // Set extruder to saved position
-    current_position[E_AXIS] = lastpos[E_AXIS];
-    destination[E_AXIS] = lastpos[E_AXIS];
+    destination[E_AXIS] = current_position[E_AXIS] = lastpos[E_AXIS];
     planner.set_e_position_mm(current_position[E_AXIS]);
 
     #if IS_KINEMATIC
diff --git a/Marlin/planner.cpp b/Marlin/planner.cpp
index 183fe0c172..d1cf89ea5b 100644
--- a/Marlin/planner.cpp
+++ b/Marlin/planner.cpp
@@ -594,13 +594,14 @@ void Planner::check_axes_activity() {
  * Planner::_buffer_line
  *
  * Add a new linear movement to the buffer.
- * Not apply the leveling.
  *
- *  x,y,z,e   - target position in mm
- *  fr_mm_s   - (target) speed of the move
- *  extruder  - target extruder
+ * Leveling and kinematics should be applied ahead of calling this.
+ *
+ *  a,b,c,e     - target positions in mm or degrees
+ *  fr_mm_s     - (target) speed of the move
+ *  extruder    - target extruder
  */
-void Planner::_buffer_line(const float &lx, const float &ly, const float &lz, const float &e, float fr_mm_s, const uint8_t extruder) {
+void Planner::_buffer_line(const float &a, const float &b, const float &c, const float &e, float fr_mm_s, const uint8_t extruder) {
   // Calculate the buffer head after we push this byte
   int next_buffer_head = next_block_index(block_buffer_head);
 
@@ -611,36 +612,36 @@ void Planner::_buffer_line(const float &lx, const float &ly, const float &lz, co
   // The target position of the tool in absolute steps
   // Calculate target position in absolute steps
   //this should be done after the wait, because otherwise a M92 code within the gcode disrupts this calculation somehow
-  long target[NUM_AXIS] = {
-    lround(lx * axis_steps_per_mm[X_AXIS]),
-    lround(ly * axis_steps_per_mm[Y_AXIS]),
-    lround(lz * axis_steps_per_mm[Z_AXIS]),
+  long target[XYZE] = {
+    lround(a * axis_steps_per_mm[X_AXIS]),
+    lround(b * axis_steps_per_mm[Y_AXIS]),
+    lround(c * axis_steps_per_mm[Z_AXIS]),
     lround(e * axis_steps_per_mm[E_AXIS])
   };
 
-  long dx = target[X_AXIS] - position[X_AXIS],
-       dy = target[Y_AXIS] - position[Y_AXIS],
-       dz = target[Z_AXIS] - position[Z_AXIS];
+  long da = target[X_AXIS] - position[X_AXIS],
+       db = target[Y_AXIS] - position[Y_AXIS],
+       dc = target[Z_AXIS] - position[Z_AXIS];
 
   /*
   SERIAL_ECHOPAIR("  Planner FR:", fr_mm_s);
   SERIAL_CHAR(' ');
   #if IS_KINEMATIC
-    SERIAL_ECHOPAIR("A:", lx);
-    SERIAL_ECHOPAIR(" (", dx);
-    SERIAL_ECHOPAIR(") B:", ly);
+    SERIAL_ECHOPAIR("A:", a);
+    SERIAL_ECHOPAIR(" (", da);
+    SERIAL_ECHOPAIR(") B:", b);
   #else
-    SERIAL_ECHOPAIR("X:", lx);
-    SERIAL_ECHOPAIR(" (", dx);
-    SERIAL_ECHOPAIR(") Y:", ly);
+    SERIAL_ECHOPAIR("X:", a);
+    SERIAL_ECHOPAIR(" (", da);
+    SERIAL_ECHOPAIR(") Y:", b);
   #endif
-  SERIAL_ECHOPAIR(" (", dy);
+  SERIAL_ECHOPAIR(" (", db);
   #if ENABLED(DELTA)
-    SERIAL_ECHOPAIR(") C:", lz);
+    SERIAL_ECHOPAIR(") C:", c);
   #else
-    SERIAL_ECHOPAIR(") Z:", lz);
+    SERIAL_ECHOPAIR(") Z:", c);
   #endif
-  SERIAL_ECHOPAIR(" (", dz);
+  SERIAL_ECHOPAIR(" (", dc);
   SERIAL_CHAR(')');
   SERIAL_EOL;
   //*/
@@ -679,24 +680,24 @@ void Planner::_buffer_line(const float &lx, const float &ly, const float &lz, co
   #if ENABLED(COREXY)
     // corexy planning
     // these equations follow the form of the dA and dB equations on http://www.corexy.com/theory.html
-    block->steps[A_AXIS] = labs(dx + dy);
-    block->steps[B_AXIS] = labs(dx - dy);
-    block->steps[Z_AXIS] = labs(dz);
+    block->steps[A_AXIS] = labs(da + db);
+    block->steps[B_AXIS] = labs(da - db);
+    block->steps[Z_AXIS] = labs(dc);
   #elif ENABLED(COREXZ)
     // corexz planning
-    block->steps[A_AXIS] = labs(dx + dz);
-    block->steps[Y_AXIS] = labs(dy);
-    block->steps[C_AXIS] = labs(dx - dz);
+    block->steps[A_AXIS] = labs(da + dc);
+    block->steps[Y_AXIS] = labs(db);
+    block->steps[C_AXIS] = labs(da - dc);
   #elif ENABLED(COREYZ)
     // coreyz planning
-    block->steps[X_AXIS] = labs(dx);
-    block->steps[B_AXIS] = labs(dy + dz);
-    block->steps[C_AXIS] = labs(dy - dz);
+    block->steps[X_AXIS] = labs(da);
+    block->steps[B_AXIS] = labs(db + dc);
+    block->steps[C_AXIS] = labs(db - dc);
   #else
     // default non-h-bot planning
-    block->steps[X_AXIS] = labs(dx);
-    block->steps[Y_AXIS] = labs(dy);
-    block->steps[Z_AXIS] = labs(dz);
+    block->steps[X_AXIS] = labs(da);
+    block->steps[Y_AXIS] = labs(db);
+    block->steps[Z_AXIS] = labs(dc);
   #endif
 
   block->steps[E_AXIS] = labs(de) * volumetric_multiplier[extruder] * flow_percentage[extruder] * 0.01 + 0.5;
@@ -720,33 +721,33 @@ void Planner::_buffer_line(const float &lx, const float &ly, const float &lz, co
     block->e_to_p_pressure = baricuda_e_to_p_pressure;
   #endif
 
-  // Compute direction bits for this block
-  uint8_t db = 0;
+  // Compute direction bit-mask for this block
+  uint8_t dm = 0;
   #if ENABLED(COREXY)
-    if (dx < 0) SBI(db, X_HEAD); // Save the real Extruder (head) direction in X Axis
-    if (dy < 0) SBI(db, Y_HEAD); // ...and Y
-    if (dz < 0) SBI(db, Z_AXIS);
-    if (dx + dy < 0) SBI(db, A_AXIS); // Motor A direction
-    if (dx - dy < 0) SBI(db, B_AXIS); // Motor B direction
+    if (da < 0) SBI(dm, X_HEAD); // Save the real Extruder (head) direction in X Axis
+    if (db < 0) SBI(dm, Y_HEAD); // ...and Y
+    if (dc < 0) SBI(dm, Z_AXIS);
+    if (da + db < 0) SBI(dm, A_AXIS); // Motor A direction
+    if (da - db < 0) SBI(dm, B_AXIS); // Motor B direction
   #elif ENABLED(COREXZ)
-    if (dx < 0) SBI(db, X_HEAD); // Save the real Extruder (head) direction in X Axis
-    if (dy < 0) SBI(db, Y_AXIS);
-    if (dz < 0) SBI(db, Z_HEAD); // ...and Z
-    if (dx + dz < 0) SBI(db, A_AXIS); // Motor A direction
-    if (dx - dz < 0) SBI(db, C_AXIS); // Motor C direction
+    if (da < 0) SBI(dm, X_HEAD); // Save the real Extruder (head) direction in X Axis
+    if (db < 0) SBI(dm, Y_AXIS);
+    if (dc < 0) SBI(dm, Z_HEAD); // ...and Z
+    if (da + dc < 0) SBI(dm, A_AXIS); // Motor A direction
+    if (da - dc < 0) SBI(dm, C_AXIS); // Motor C direction
   #elif ENABLED(COREYZ)
-    if (dx < 0) SBI(db, X_AXIS);
-    if (dy < 0) SBI(db, Y_HEAD); // Save the real Extruder (head) direction in Y Axis
-    if (dz < 0) SBI(db, Z_HEAD); // ...and Z
-    if (dy + dz < 0) SBI(db, B_AXIS); // Motor B direction
-    if (dy - dz < 0) SBI(db, C_AXIS); // Motor C direction
+    if (da < 0) SBI(dm, X_AXIS);
+    if (db < 0) SBI(dm, Y_HEAD); // Save the real Extruder (head) direction in Y Axis
+    if (dc < 0) SBI(dm, Z_HEAD); // ...and Z
+    if (db + dc < 0) SBI(dm, B_AXIS); // Motor B direction
+    if (db - dc < 0) SBI(dm, C_AXIS); // Motor C direction
   #else
-    if (dx < 0) SBI(db, X_AXIS);
-    if (dy < 0) SBI(db, Y_AXIS);
-    if (dz < 0) SBI(db, Z_AXIS);
+    if (da < 0) SBI(dm, X_AXIS);
+    if (db < 0) SBI(dm, Y_AXIS);
+    if (dc < 0) SBI(dm, Z_AXIS);
   #endif
-  if (de < 0) SBI(db, E_AXIS);
-  block->direction_bits = db;
+  if (de < 0) SBI(dm, E_AXIS);
+  block->direction_bits = dm;
 
   block->active_extruder = extruder;
 
@@ -859,29 +860,29 @@ void Planner::_buffer_line(const float &lx, const float &ly, const float &lz, co
   #if ENABLED(COREXY) || ENABLED(COREXZ) || ENABLED(COREYZ)
     float delta_mm[7];
     #if ENABLED(COREXY)
-      delta_mm[X_HEAD] = dx * steps_to_mm[A_AXIS];
-      delta_mm[Y_HEAD] = dy * steps_to_mm[B_AXIS];
-      delta_mm[Z_AXIS] = dz * steps_to_mm[Z_AXIS];
-      delta_mm[A_AXIS] = (dx + dy) * steps_to_mm[A_AXIS];
-      delta_mm[B_AXIS] = (dx - dy) * steps_to_mm[B_AXIS];
+      delta_mm[X_HEAD] = da * steps_to_mm[A_AXIS];
+      delta_mm[Y_HEAD] = db * steps_to_mm[B_AXIS];
+      delta_mm[Z_AXIS] = dc * steps_to_mm[Z_AXIS];
+      delta_mm[A_AXIS] = (da + db) * steps_to_mm[A_AXIS];
+      delta_mm[B_AXIS] = (da - db) * steps_to_mm[B_AXIS];
     #elif ENABLED(COREXZ)
-      delta_mm[X_HEAD] = dx * steps_to_mm[A_AXIS];
-      delta_mm[Y_AXIS] = dy * steps_to_mm[Y_AXIS];
-      delta_mm[Z_HEAD] = dz * steps_to_mm[C_AXIS];
-      delta_mm[A_AXIS] = (dx + dz) * steps_to_mm[A_AXIS];
-      delta_mm[C_AXIS] = (dx - dz) * steps_to_mm[C_AXIS];
+      delta_mm[X_HEAD] = da * steps_to_mm[A_AXIS];
+      delta_mm[Y_AXIS] = db * steps_to_mm[Y_AXIS];
+      delta_mm[Z_HEAD] = dc * steps_to_mm[C_AXIS];
+      delta_mm[A_AXIS] = (da + dc) * steps_to_mm[A_AXIS];
+      delta_mm[C_AXIS] = (da - dc) * steps_to_mm[C_AXIS];
     #elif ENABLED(COREYZ)
-      delta_mm[X_AXIS] = dx * steps_to_mm[X_AXIS];
-      delta_mm[Y_HEAD] = dy * steps_to_mm[B_AXIS];
-      delta_mm[Z_HEAD] = dz * steps_to_mm[C_AXIS];
-      delta_mm[B_AXIS] = (dy + dz) * steps_to_mm[B_AXIS];
-      delta_mm[C_AXIS] = (dy - dz) * steps_to_mm[C_AXIS];
+      delta_mm[X_AXIS] = da * steps_to_mm[X_AXIS];
+      delta_mm[Y_HEAD] = db * steps_to_mm[B_AXIS];
+      delta_mm[Z_HEAD] = dc * steps_to_mm[C_AXIS];
+      delta_mm[B_AXIS] = (db + dc) * steps_to_mm[B_AXIS];
+      delta_mm[C_AXIS] = (db - dc) * steps_to_mm[C_AXIS];
     #endif
   #else
     float delta_mm[4];
-    delta_mm[X_AXIS] = dx * steps_to_mm[X_AXIS];
-    delta_mm[Y_AXIS] = dy * steps_to_mm[Y_AXIS];
-    delta_mm[Z_AXIS] = dz * steps_to_mm[Z_AXIS];
+    delta_mm[X_AXIS] = da * steps_to_mm[X_AXIS];
+    delta_mm[Y_AXIS] = db * steps_to_mm[Y_AXIS];
+    delta_mm[Z_AXIS] = dc * steps_to_mm[Z_AXIS];
   #endif
   delta_mm[E_AXIS] = 0.01 * (de * steps_to_mm[E_AXIS]) * volumetric_multiplier[extruder] * flow_percentage[extruder];
 
@@ -1184,12 +1185,12 @@ void Planner::_buffer_line(const float &lx, const float &ly, const float &lz, co
  * On CORE machines stepper ABC will be translated from the given XYZ.
  */
 
-void Planner::_set_position_mm(const float &lx, const float &ly, const float &lz, const float &e) {
-  long nx = position[X_AXIS] = lround(lx * axis_steps_per_mm[X_AXIS]),
-       ny = position[Y_AXIS] = lround(ly * axis_steps_per_mm[Y_AXIS]),
-       nz = position[Z_AXIS] = lround(lz * axis_steps_per_mm[Z_AXIS]),
+void Planner::_set_position_mm(const float &a, const float &b, const float &c, const float &e) {
+  long na = position[X_AXIS] = lround(a * axis_steps_per_mm[X_AXIS]),
+       nb = position[Y_AXIS] = lround(b * axis_steps_per_mm[Y_AXIS]),
+       nc = position[Z_AXIS] = lround(c * axis_steps_per_mm[Z_AXIS]),
        ne = position[E_AXIS] = lround(e * axis_steps_per_mm[E_AXIS]);
-  stepper.set_position(nx, ny, nz, ne);
+  stepper.set_position(na, nb, nc, ne);
   previous_nominal_speed = 0.0; // Resets planner junction speeds. Assumes start from rest.
 
   memset(previous_speed, 0, sizeof(previous_speed));
diff --git a/Marlin/planner.h b/Marlin/planner.h
index 1d7e65a25d..785c6ac512 100644
--- a/Marlin/planner.h
+++ b/Marlin/planner.h
@@ -232,27 +232,32 @@ class Planner {
     /**
      * Planner::_buffer_line
      *
-     * Add a new linear movement to the buffer.
-     * Doesn't apply the leveling.
+     * Add a new direct linear movement to the buffer.
+     *
+     * Leveling and kinematics should be applied ahead of this.
      *
-     *  x,y,z,e   - target position in mm
-     *  fr_mm_s   - (target) speed of the move
+     *  a,b,c,e   - target position in mm or degrees
+     *  fr_mm_s   - (target) speed of the move (mm/s)
      *  extruder  - target extruder
      */
-    static void _buffer_line(const float &lx, const float &ly, const float &lz, const float &e, float fr_mm_s, const uint8_t extruder);
+    static void _buffer_line(const float &a, const float &b, const float &c, const float &e, float fr_mm_s, const uint8_t extruder);
 
-    static void _set_position_mm(const float &lx, const float &ly, const float &lz, const float &e);
+    static void _set_position_mm(const float &a, const float &b, const float &c, const float &e);
 
     /**
      * Add a new linear movement to the buffer.
      * The target is NOT translated to delta/scara
      *
-     *  x,y,z,e   - target position in mm
-     *  fr_mm_s   - (target) speed of the move (mm/s)
-     *  extruder  - target extruder
+     * Leveling will be applied to input on cartesians.
+     * Kinematic machines should call buffer_line_kinematic (for leveled moves).
+     * (Cartesians may also call buffer_line_kinematic.)
+     *
+     *  lx,ly,lz,e   - target position in mm or degrees
+     *  fr_mm_s      - (target) speed of the move (mm/s)
+     *  extruder     - target extruder
      */
     static FORCE_INLINE void buffer_line(ARG_X, ARG_Y, ARG_Z, const float &e, float fr_mm_s, const uint8_t extruder) {
-      #if PLANNER_LEVELING && ! IS_KINEMATIC
+      #if PLANNER_LEVELING && IS_CARTESIAN
         apply_leveling(lx, ly, lz);
       #endif
       _buffer_line(lx, ly, lz, e, fr_mm_s, extruder);
@@ -267,7 +272,7 @@ class Planner {
      *  fr_mm_s  - (target) speed of the move (mm/s)
      *  extruder - target extruder
      */
-     static FORCE_INLINE void buffer_line_kinematic(const float target[NUM_AXIS], float fr_mm_s, const uint8_t extruder) {
+    static FORCE_INLINE void buffer_line_kinematic(const float target[XYZE], float fr_mm_s, const uint8_t extruder) {
       #if PLANNER_LEVELING
         float pos[XYZ] = { target[X_AXIS], target[Y_AXIS], target[Z_AXIS] };
         apply_leveling(pos);
@@ -292,7 +297,7 @@ class Planner {
      * Clears previous speed values.
      */
     static FORCE_INLINE void set_position_mm(ARG_X, ARG_Y, ARG_Z, const float &e) {
-      #if PLANNER_LEVELING && ! IS_KINEMATIC
+      #if PLANNER_LEVELING && IS_CARTESIAN
         apply_leveling(lx, ly, lz);
       #endif
       _set_position_mm(lx, ly, lz, e);
diff --git a/Marlin/stepper.cpp b/Marlin/stepper.cpp
index f2800ebe56..bd4aa85b65 100644
--- a/Marlin/stepper.cpp
+++ b/Marlin/stepper.cpp
@@ -953,7 +953,7 @@ void Stepper::synchronize() { while (planner.blocks_queued()) idle(); }
  * This allows get_axis_position_mm to correctly
  * derive the current XYZ position later on.
  */
-void Stepper::set_position(const long& x, const long& y, const long& z, const long& e) {
+void Stepper::set_position(const long &a, const long &b, const long &c, const long &e) {
 
   synchronize(); // Bad to set stepper counts in the middle of a move
 
@@ -962,37 +962,37 @@ void Stepper::set_position(const long& x, const long& y, const long& z, const lo
   #if ENABLED(COREXY)
     // corexy positioning
     // these equations follow the form of the dA and dB equations on http://www.corexy.com/theory.html
-    count_position[A_AXIS] = x + y;
-    count_position[B_AXIS] = x - y;
-    count_position[Z_AXIS] = z;
+    count_position[A_AXIS] = a + b;
+    count_position[B_AXIS] = a - b;
+    count_position[Z_AXIS] = c;
   #elif ENABLED(COREXZ)
     // corexz planning
-    count_position[A_AXIS] = x + z;
-    count_position[Y_AXIS] = y;
-    count_position[C_AXIS] = x - z;
+    count_position[A_AXIS] = a + c;
+    count_position[Y_AXIS] = b;
+    count_position[C_AXIS] = a - c;
   #elif ENABLED(COREYZ)
     // coreyz planning
-    count_position[X_AXIS] = x;
-    count_position[B_AXIS] = y + z;
-    count_position[C_AXIS] = y - z;
+    count_position[X_AXIS] = a;
+    count_position[B_AXIS] = y + c;
+    count_position[C_AXIS] = y - c;
   #else
     // default non-h-bot planning
-    count_position[X_AXIS] = x;
-    count_position[Y_AXIS] = y;
-    count_position[Z_AXIS] = z;
+    count_position[X_AXIS] = a;
+    count_position[Y_AXIS] = b;
+    count_position[Z_AXIS] = c;
   #endif
 
   count_position[E_AXIS] = e;
   CRITICAL_SECTION_END;
 }
 
-void Stepper::set_position(const AxisEnum &axis, const long& v) {
+void Stepper::set_position(const AxisEnum &axis, const long &v) {
   CRITICAL_SECTION_START;
   count_position[axis] = v;
   CRITICAL_SECTION_END;
 }
 
-void Stepper::set_e_position(const long& e) {
+void Stepper::set_e_position(const long &e) {
   CRITICAL_SECTION_START;
   count_position[E_AXIS] = e;
   CRITICAL_SECTION_END;
diff --git a/Marlin/stepper.h b/Marlin/stepper.h
index 3e31f82d19..77e67fcad7 100644
--- a/Marlin/stepper.h
+++ b/Marlin/stepper.h
@@ -188,9 +188,9 @@ class Stepper {
     //
     // Set the current position in steps
     //
-    static void set_position(const long& x, const long& y, const long& z, const long& e);
-    static void set_position(const AxisEnum& a, const long& v);
-    static void set_e_position(const long& e);
+    static void set_position(const long &a, const long &b, const long &c, const long &e);
+    static void set_position(const AxisEnum &a, const long &v);
+    static void set_e_position(const long &e);
 
     //
     // Set direction bits for all steppers