I have not tried the windows version but when you do the PI build can you look into the key buffer?
I am using the TechKeys board and it seems to overload CM when holding down any axis move key for a bit. Sometimes a short bit. The move will pause and CM shows busy. It would resume until you let up on the key and let it clear.
I assumed it was a hardware issue but when I open a terminal window the keys just keep scrolling away as long as I have it pressed. The touch screen does not have the issue so I am using it to get close and then the TechKeys for fine adjustments now.