I used to use the Marlin 1.x software that would level the bed by probing the 4 corners of my print bed (a long time ago, it's been at least 2 years since I used my printer, wasn't able to set it up after I moved).
My slicer had G-code that would kick off a level at the beginning of every print.
I've upgraded to Marlin 2.x and now I'm setting up UBL. It takes quite a bit of time to probe the bed with UBL, like 10 minutes. The steps tell me to save to EEPROM and my firmware is set up to restore after every G28 (Home).
How often should I do a G29 (Bed Leveling)? Should I do it every print? Every 10 prints? 100 Prints? Or when I see that the print isn't sticking to the bed?
EDIT: I went from a Grid-style ABL to UBL because UBL merges the benefits of a few different leveling techniques so theoretically it should be better. I understand I could just go back to grid-style bed leveling but even when it was working, for some reason the z-offset would shift ever so slightly every few prints and I would have to change configure it in my slicer. I'd like to try UBL and see if I can leave my printer for a while without having to fidget with the Z-offset.