Not true - there are no decimals. Everything sent to a Ruida controller is done in microns, expressed as integers, so the numbers are perfectly repeatable with no error. All computations done by LightBurn are done in absolute locations, converted to microns, then offset from the origin point, to ensure precision. Any relative values that are sent are also computed from the micron coordinates. I can assure you there are no accumulated errors either in the software or the controller.
What most people fail to account for is resonance. Acceleration and speed play the largest roles, but your motion system has mass and flex, which means vibration, and if you ask it to change direction very rapidly in just the right places, that vibration can work against you and cause lost steps.
Watch what happens to the mass on the right when the platform hits 4hz at 1:15 sec into the video:
The belts in your laser have tension, and the metal has flex, so the system will have a natural resonance (probably a different frequency for each axis). If you make direction changes that happen to coincide with that resonant frequency at just the right times, you’ll amplify the resonance. Lowering acceleration will combat this because you aren’t imparting as much energy into it, and with the acceleration low enough, the mechanical damping will kill the resonance before it builds.
You haven’t said whether the issue is on the X, the Y, or both. What speed and accelerations are you running, and how large is your system?