diff --git a/Marlin/src/module/planner.cpp b/Marlin/src/module/planner.cpp
index 1b70d748e4..70abe16667 100644
--- a/Marlin/src/module/planner.cpp
+++ b/Marlin/src/module/planner.cpp
@@ -1789,11 +1789,12 @@ bool Planner::_buffer_steps(const xyze_long_t &target
   if (cleaning_buffer_counter) return false;
 
   // Fill the block with the specified movement
-  if (!_populate_block(block, false, target
-    OPTARG(HAS_POSITION_FLOAT, target_float)
-    OPTARG(HAS_DIST_MM_ARG, cart_dist_mm)
-    , fr_mm_s, extruder, millimeters
-  )) {
+  if (!_populate_block(block, target
+        OPTARG(HAS_POSITION_FLOAT, target_float)
+        OPTARG(HAS_DIST_MM_ARG, cart_dist_mm)
+        , fr_mm_s, extruder, millimeters
+      )
+  ) {
     // Movement was not queued, probably because it was too short.
     //  Simply accept that as movement queued and done
     return true;
@@ -1820,17 +1821,24 @@ bool Planner::_buffer_steps(const xyze_long_t &target
 }
 
 /**
- * Planner::_populate_block
+ * @brief Populate a block in preparation for insertion
+ * @details Populate the fields of a new linear movement block
+ *          that will be added to the queue and processed soon
+ *          by the Stepper ISR.
  *
- * Fills a new linear movement in the block (in terms of steps).
+ * @param block         A block to populate
+ * @param target        Target position in steps units
+ * @param target_float  Target position in native mm
+ * @param cart_dist_mm  The pre-calculated move lengths for all axes, in mm
+ * @param fr_mm_s       (target) speed of the move
+ * @param extruder      target extruder
+ * @param millimeters   A pre-calculated linear distance for the move, in mm,
+ *                      or 0.0 to have the distance calculated here.
  *
- *  target      - target position in steps units
- *  fr_mm_s     - (target) speed of the move
- *  extruder    - target extruder
- *
- * Returns true if movement is acceptable, false otherwise
+ * @return  true if movement is acceptable, false otherwise
  */
-bool Planner::_populate_block(block_t * const block, bool split_move,
+bool Planner::_populate_block(
+  block_t * const block,
   const abce_long_t &target
   OPTARG(HAS_POSITION_FLOAT, const xyze_pos_t &target_float)
   OPTARG(HAS_DIST_MM_ARG, const xyze_float_t &cart_dist_mm)
@@ -2774,9 +2782,8 @@ bool Planner::_populate_block(block_t * const block, bool split_move,
   // Initialize block entry speed. Compute based on deceleration to user-defined MINIMUM_PLANNER_SPEED.
   const float v_allowable_sqr = max_allowable_speed_sqr(-block->acceleration, sq(float(MINIMUM_PLANNER_SPEED)), block->millimeters);
 
-  // If we are trying to add a split block, start with the
-  // max. allowed speed to avoid an interrupted first move.
-  block->entry_speed_sqr = !split_move ? sq(float(MINIMUM_PLANNER_SPEED)) : _MIN(vmax_junction_sqr, v_allowable_sqr);
+  // Start with the minimum allowed speed
+  block->entry_speed_sqr = sq(float(MINIMUM_PLANNER_SPEED));
 
   // Initialize planner efficiency flags
   // Set flag if block will always reach maximum junction speed regardless of entry/exit speeds.
diff --git a/Marlin/src/module/planner.h b/Marlin/src/module/planner.h
index 38f958c10f..42434002be 100644
--- a/Marlin/src/module/planner.h
+++ b/Marlin/src/module/planner.h
@@ -737,18 +737,23 @@ class Planner {
     );
 
     /**
-     * Planner::_populate_block
+     * @brief Populate a block in preparation for insertion
+     * @details Populate the fields of a new linear movement block
+     *          that will be added to the queue and processed soon
+     *          by the Stepper ISR.
      *
-     * Fills a new linear movement in the block (in terms of steps).
+     * @param block         A block to populate
+     * @param target        Target position in steps units
+     * @param target_float  Target position in native mm
+     * @param cart_dist_mm  The pre-calculated move lengths for all axes, in mm
+     * @param fr_mm_s       (target) speed of the move
+     * @param extruder      target extruder
+     * @param millimeters   A pre-calculated linear distance for the move, in mm,
+     *                      or 0.0 to have the distance calculated here.
      *
-     *  target      - target position in steps units
-     *  fr_mm_s     - (target) speed of the move
-     *  extruder    - target extruder
-     *  millimeters - the length of the movement, if known
-     *
-     * Returns true is movement is acceptable, false otherwise
+     * @return  true if movement is acceptable, false otherwise
      */
-    static bool _populate_block(block_t * const block, bool split_move, const xyze_long_t &target
+    static bool _populate_block(block_t * const block, const xyze_long_t &target
       OPTARG(HAS_POSITION_FLOAT, const xyze_pos_t &target_float)
       OPTARG(HAS_DIST_MM_ARG, const xyze_float_t &cart_dist_mm)
       , feedRate_t fr_mm_s, const uint8_t extruder, const_float_t millimeters=0.0