It's not my machine, and it's a bit too expensive to risk breaking it, besides speed setting is strictly software thing (even if just firmware of its embedded microcontroller) - just speed at which it gives pulses to the steppers. I honestly doubt I'd be able to hack the firmware to limit the max speed or accept other file formats.

As I said, the problem is in software, the exported file isn't fully compatibile. I can get the machine to move as slow as I wish if I use the dedicated software, so I'd rather try to hack the file format and write my own conversion tool that would connect settings invocation from the one file with move commands from the other.

The situation isn't too bad too, the conditions for the drill breaker movement are pretty much contained (I know what operations trigger it and just don't perform them) and while I can't get below the 1mm/s XY movement speed, I can set 0.01mm Z steps so the drill slides over the surface taking only very little of it with each pass. I still have to drill all the through holes at home by myself though.

As to speed, the machine can do 8000RPM at most, sounds like not quite enough for the carbide bits, doesn't it?