I already responded to your thread with extended explanation based on your new screenshots. It was tagged that way for a similar reason as to why you are hesitant to post the question in G&R (which, to be honest, is probably fine anyway).
https://github.com/SaltimusPrime/WacomAreaChanger/releases this may be of help to you, i dunno if ittl work with your tablet but its worth a shot. then you could load the backup by clicking on the wacom area button and clicking on "load from backup" (as shown in picture)Funny thing is damn wacom backups themselves dont even work properly half the time. i.e if i have ot set to full screen when i make the backup but i do indeed have a portion setup i can swap to with the press of a check circle, the backup will just wipe that as if i didnt even have one set even if I had that there when i made the backup lol.
you alternatively could just find the # of mm in a wacom unit and convert it from there