🎨 Misc. IS cleanup

Marlin/src/gcode/feature/input_shaping/M593.cpp

@@ -49,8 +49,8 @@ void GcodeSuite::M593_report(const bool forReplay/*=true*/) {
  *  D<factor>    Set the zeta/damping factor. If axes (X, Y, etc.) are not specified, set for all axes.
  *  F<frequency> Set the frequency. If axes (X, Y, etc.) are not specified, set for all axes.
  *  T[map]       Input Shaping type, 0:ZV, 1:EI, 2:2H EI (not implemented yet)
- *  X<1>         Set the given parameters only for the X axis.
- *  Y<1>         Set the given parameters only for the Y axis.
+ *  X            Set the given parameters only for the X axis.
+ *  Y            Set the given parameters only for the Y axis.
  */
 void GcodeSuite::M593() {
   if (!parser.seen_any()) return M593_report();

Marlin/src/module/stepper.cpp

@@ -3015,7 +3015,7 @@ void Stepper::init() {
 
   void Stepper::set_shaping_frequency(const AxisEnum axis, const float freq) {
     // enabling or disabling shaping whilst moving can result in lost steps
-    Planner::synchronize();
+    planner.synchronize();
 
     const bool was_on = hal.isr_state();
     hal.isr_off();