Solved Z offset (?) in Prusa Slicer?

Been experimenting with Prusa Slicer, v 2.52. While my very first print seemed to do well, since then various problems.

One may be the first layer, the infamous Z offset. I say that as the first layer seem a bit thin. In Prusa slicer under Printer Settings there is a Z-Offset which may be the setting in question. It seems to suggest it is only set when the Z limit is "wrong" (so the nozzle is not zero from the bed). Says if the nozzle is 0.03 from the bed to set the offset to -0.03.

Rather than fiddle all day, any wisdom to share?

I should add that I am also delving into OctoPrint, but see no setting there for Z offset in printer profiles.

 

Trial and error have given me a reasonable offset.