diff --git a/Marlin/src/feature/bedlevel/ubl/ubl_motion.cpp b/Marlin/src/feature/bedlevel/ubl/ubl_motion.cpp
index e6eec0de63fd..9fa2257dc8a6 100644
--- a/Marlin/src/feature/bedlevel/ubl/ubl_motion.cpp
+++ b/Marlin/src/feature/bedlevel/ubl/ubl_motion.cpp
@@ -36,8 +36,18 @@
 #include "../../../MarlinCore.h"
 #include <math.h>
 
+//#define DEBUG_UBL_MOTION
+#define DEBUG_OUT ENABLED(DEBUG_UBL_MOTION)
+#include "../../../core/debug_out.h"
+
 #if !UBL_SEGMENTED
 
+  // TODO: The first and last parts of a move might result in very short segment(s)
+  //       after getting split on the cell boundary, so moves like that should not
+  //       get split. This will be most common for moves that start/end near the
+  //       corners of cells. To fix the issue, simply check if the start/end of the line
+  //       is very close to a cell boundary in advance and don't split the line there.
+
   void unified_bed_leveling::line_to_destination_cartesian(const_feedRate_t scaled_fr_mm_s, const uint8_t extruder) {
     /**
      * Much of the nozzle movement will be within the same cell. So we will do as little computation
@@ -176,7 +186,9 @@
           dest.z += z0;
           planner.buffer_segment(dest, scaled_fr_mm_s, extruder);
 
-        } //else printf("FIRST MOVE PRUNED  ");
+        }
+        else
+          DEBUG_ECHOLNPGM("[ubl] skip Y segment");
       }
 
       // At the final destination? Usually not, but when on a Y Mesh Line it's completed.
@@ -225,7 +237,9 @@
           dest.z += z0;
           if (!planner.buffer_segment(dest, scaled_fr_mm_s, extruder)) break;
 
-        } //else printf("FIRST MOVE PRUNED  ");
+        }
+        else
+          DEBUG_ECHOLNPGM("[ubl] skip Y segment");
       }
 
       if (xy_pos_t(current_position) != xy_pos_t(end))
diff --git a/Marlin/src/gcode/motion/G2_G3.cpp b/Marlin/src/gcode/motion/G2_G3.cpp
index e7889f391840..ade014fcea99 100644
--- a/Marlin/src/gcode/motion/G2_G3.cpp
+++ b/Marlin/src/gcode/motion/G2_G3.cpp
@@ -343,8 +343,10 @@ void plan_arc(
       #endif
 
       if (!planner.buffer_line(raw, scaled_fr_mm_s, active_extruder, 0
-        OPTARG(SCARA_FEEDRATE_SCALING, inv_duration), i > 1 ? radius : 0.0))
-        break;
+            OPTARG(SCARA_FEEDRATE_SCALING, inv_duration)
+            , i > 1 ? radius : 0
+          )
+      ) break;
     }
   }
 
diff --git a/Marlin/src/module/planner.cpp b/Marlin/src/module/planner.cpp
index 33a0edc700b7..e1f689471f0c 100644
--- a/Marlin/src/module/planner.cpp
+++ b/Marlin/src/module/planner.cpp
@@ -1782,7 +1782,7 @@ void Planner::synchronize() { while (busy()) idle(); }
 bool Planner::_buffer_steps(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
+  , feedRate_t fr_mm_s, const uint8_t extruder, const_float_t millimeters/*=0.0*/
   OPTARG(ARC_SUPPORT, const_float_t arc_radius/*=0.0*/)
 ) {
 
@@ -1797,11 +1797,12 @@ bool Planner::_buffer_steps(const xyze_long_t &target
 
   // 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
-    OPTARG(ARC_SUPPORT, arc_radius)
-  )) {
+        OPTARG(HAS_POSITION_FLOAT, target_float)
+        OPTARG(HAS_DIST_MM_ARG, cart_dist_mm)
+        , fr_mm_s, extruder, millimeters
+        OPTARG(ARC_SUPPORT, arc_radius)
+      )
+  ) {
     // Movement was not queued, probably because it was too short.
     //  Simply accept that as movement queued and done
     return true;
@@ -1859,36 +1860,8 @@ bool Planner::_populate_block(block_t * const block, bool split_move,
   );
 
   /* <-- add a slash to enable
-    SERIAL_ECHOLNPGM(
-      "  _populate_block FR:", fr_mm_s,
-      " A:", target.a, " (", da, " steps)"
-      #if HAS_Y_AXIS
-        " B:", target.b, " (", db, " steps)"
-      #endif
-      #if HAS_Z_AXIS
-        " C:", target.c, " (", dc, " steps)"
-      #endif
-      #if HAS_I_AXIS
-        " " STR_I ":", target.i, " (", di, " steps)"
-      #endif
-      #if HAS_J_AXIS
-        " " STR_J ":", target.j, " (", dj, " steps)"
-      #endif
-      #if HAS_K_AXIS
-        " " STR_K ":", target.k, " (", dk, " steps)"
-      #endif
-      #if HAS_U_AXIS
-        " " STR_U ":", target.u, " (", du, " steps)"
-      #endif
-      #if HAS_V_AXIS
-        " " STR_V ":", target.v, " (", dv, " steps)"
-      #endif
-      #if HAS_W_AXIS
-        " " STR_W ":", target.w, " (", dw, " steps)"
-      #if HAS_EXTRUDERS
-        " E:", target.e, " (", de, " steps)"
-      #endif
-    );
+    #define _ALINE(A) " A:", target[_AXIS(A)], " (", int32_t(target[_AXIS(A)] - position[_AXIS(A)]), " steps)"
+    SERIAL_ECHOLNPGM("  _populate_block FR:", fr_mm_s, LOGICAL_AXIS_MAP(_ALINE));
   //*/
 
   #if EITHER(PREVENT_COLD_EXTRUSION, PREVENT_LENGTHY_EXTRUDE)
@@ -2653,14 +2626,13 @@ bool Planner::_populate_block(block_t * const block, bool split_move,
         // Convert delta vector to unit vector
         xyze_float_t junction_unit_vec = unit_vec - prev_unit_vec;
         normalize_junction_vector(junction_unit_vec);
+
         const float junction_acceleration = limit_value_by_axis_maximum(block->acceleration, junction_unit_vec);
 
-        #if ENABLED(ARC_SUPPORT)
-          if (arc_radius > 0.0)
-            vmax_junction_sqr = junction_acceleration * arc_radius;
-          else
-        #endif
-        {
+        if (TERN0(ARC_SUPPORT, arc_radius)) {
+          TERN_(ARC_SUPPORT, vmax_junction_sqr = junction_acceleration * arc_radius);
+        }
+        else {
           NOLESS(junction_cos_theta, -0.999999f); // Check for numerical round-off to avoid divide by zero.
 
           const float sin_theta_d2 = SQRT(0.5f * (1.0f - junction_cos_theta)); // Trig half angle identity. Always positive.