Standard disclaimers apply, I'm not responsible for people bricking their CPAPs or other life support equipment with this information, you live your own life the way you choose. Please don't screw around with a "live" machine hooked to a patient cough.
I was trying to see what the differences were between the lowest-end "start" CPAP and the highest end - while the firmware would flash over, the menu controls wouldn't work due to the changes made on the low end model - but the therapy start/stop did work (and it was delivering the correct therapy I programmed in via SD card with the clinician software).