Re: M600 question

OK was not sure!

But let's think about this. I have a filament run out sensor so I tested the line of code.

M600 X10 Y10 Z10 L100 // Pause Print

It worked as expected. So You actually do not need a run-out sensor.
You can enable code as if you had a run-out sensor and place a jumper across the pins to simulate the filament in place.
Then the commands will work as expected.

#define FILAMENT_RUNOUT_SENSOR // Uncomment for defining a filament runout sensor such as a mechanical or opto endstop to check the existence of filament
#if ENABLED(FILAMENT_RUNOUT_SENSOR)
#define FIL_RUNOUT_INVERTING true // set to true to invert the logic of the sensor.
//#define ENDSTOPPULLUP_FIL_RUNOUT // Uncomment to use internal pullup for filament runout pins if the sensor is defined.
#define FILAMENT_RUNOUT_SCRIPT "M600" // Move this line
#endif

In pins.RAMPS.h // Or whatever your board uses for pins {this is just an example}
// define digital pin 4 for the filament runout sensor. Use the RAMPS 1.4 digital input 4 on the servos connector
// #define FIL_RUNOUT_PIN 4
// define X_MAX_PIN 2 for the filament runout sensor.
#define FIL_RUNOUT_PIN 2

And install a jumper to simulate a sensor that it has filament. My 3D Printer does not use Z-Max EndStop so I use it for the Run-out sensor

My run-out sensor schematic, Sensor is a little larger that a quarter and has a 4 Pin connector the Controller has a 3 pin connector. Led on when filament present.
[attachment 99552 FilamentRun-out.jpg]