I am one of those who went through the trouble of finding the right offset and changed my printer profile. Then when I started printing PLA and not PETG, of course it varied and I needed to start over.
I ended up adjusting the first layer flow rate instead of the height. I read up and eventually figured out that this might impact accuracy of the dimensions, tolerances, etc. I went back and did this for PETG and did many before and after calibration cubes and THEY WERE THE SAME.
So, given that printer settings apply at the printer level and not filament level, it’s not ideal to have this ‘change’ sit in the printer config which will need changing when using different filament types. It also is a PITA to debug the z-hight to get it perfect (can’t do them on the same printing run unless you modify gcode by hand). The first layer flow rate is super easy to dial in thanks to this print.
I would love to be proven wrong because I honestly have no clue how the z-height corresponds to the first layer flow and why that doesn’t mess up the rest of the model, but I do think the first layer is more accurate now that I’m not adjusting the z-height. No elephant foot.