Thank you Jerry and John for your suggestions. Right now the only computer I can experiment with is my actual 'production' computer and I don't feel confident enough to go any further installing the suggested script. Instead I was trying to go the Stellarmate route. Unfortunately it crashed at 99% update and after that does not start up anymore (not even after a fresh install of the OS...). I guess something happened with the microSD card.
Anyway, I think I'll leave this one for early January when the update comes out. For now there is the workaround with setting backlash to 1, and in the new release I can select the proper settings.
Thank you again John for all the work you put into solving this issue.