On my old PRT-Alpha, if I remember correctly, the JOG command enabled the stepper driver to change the number of steps per revolution from 10X to 1X (or 1X to 10X). The Alpha drivers could send two different steps per revolution 1X and 10X. I'm wondering if the underlying problem shown by changing the J3 command to a M3 command relates to the 1X vs the 10X step resolution and if that could be solved by changing the jog speeds/ramping?