I see you can set the backlash in the EqMod control panel, how would you know the values to put in please?
Is there a method or is it guess work?

I recently had a chance to try it with guiding calibration. If you have a guidescope you can do a calibration and while calibrating
just observe how long/many pulses it takes to see the star move. For example when it starts to calibrate RA+ I usually dont see any delay because the mount already move in RA+ (sideral), after that it tries RA- and there you can find out (see) how long the delay is for the mount to move to the opposite. Same for DEC+/DEC-. If you think there is a delay and the star needs some time to move to the opposite just add some backlash to the axis. I usually start with 50 steps. Then try another calibration and slowy find the right value until you mount moves reversed direction without any delay.

[Edit2:] I ended with backlash RA:30 and DEC:270 for my HEQ5 mount (synscan).

[Edit:] That would be a nice little feature to have this backlash detection done automatic by some kind of calibration. I am shure this can be done by taking serveral frames of the star and messuring the delay in both axis.

I have had some trouble with backlash. Are you doing this setting within the INDI settings for the mount, or via the Mount itself such as the hand controller?

Thank you

no handcontroller, since I discovered the EQDirect cable my hand box is buried in the basement. I do this just with Ekos/Indi via the guiding-calibration part because that gives the best visual feedback of the mounts motion