From what I can see the Track Mode property is expected to be used to control various tracking rates - Sidereal, Solar, lunar etc., but on the Celestron driver it is used to control a Celestron track mode property that can be set to Off, AltAz, Equatorial North or Equatorial South.

I think this should be changed. I can change the Track Mode so it can set the track rate, at least for the eqatorial mounts. I'll retain the current mode, renamed to Celestron Track Mode. The control doesn't seem to be available for the fork mounts.

If there are no objections I'll do this.

YES!! I actually had this on a TODO list, but THANK YOU for taking care of it! You're absolutely right, this should behave like it does for other drivers. This would also lead the way to custom tracking (like iOptronv3 driver, check it out).