For some engraving jobs, “megabytes” will be on the low side.
One assumption that has proven true, over and over again, is that the laser controller’s USB hardware is borderline inadequate, driven by relentless cost optimization.
In addition, the USB standards were never intended to cope with low-budget PCBs switching high-current lasers using MOSFET drivers and marginal power supplies.
Mash that together with the cheapest possible USB cable and you get all the USB-related problems washing ashore around here.