@vicious1 setting jumpers won’t have the effect you want because the commands are generated buy the laser software. They’re going to get queued and parsed by marlin regardless of stepper settings. Each pixel in the image can potentially have a different grayscale value so each pixel has it’s own g1 move and power command assigned to it. Bryan has done good work to optimize moves with matching power values but In the end this is the nature of grayscale engraving. I think your original suggestion t look at acceleration settings is still a possible cause of ryans problem. The laser gcode is produced with a global feedrate that remainsv constant. If accel settings are too low then they could easily trip the machine up with such a fast flow of tiny movements.