Multiple build plates? How do deal with offsets?

I have the original build plate that came with my Neptune 4 Plus. I exchanged it for a Wham Bam carbon Fibre one, but have another PEX plate on the way. The build plate is level, but the plates are all different thicknesses.

I see in Cura you can add and choose the build plate, but I'm a little confused how to deal with the offsets.

What is the process in the software and printer for dealing with multiple build plates?

Thanks!