Here's how i see it working, this version is untested yet.
G28.1 finds the surface
I know that at the point the probe switch trips, there is a fixed gap between my torch and the metal of whatever I set in the offset box so lets just tell the DRO what the gap is i.e. it's current position, no need to be zeroing and going up and down, just tell it where it is.
The double inc/abs changes are because i have no idea what will happen if i probe when in incremental mode as i only ever run in abs mode, may work, may not.
I figured if it does no harm then just switch back and forth.
The G04's are dubious, without the first one it makes my Z motor screech for some unknown reason, maybe trying to move the Z at the current rapid speed which it cannot do??? Is there a "F" parameter for the probing, maybe throwing in a F1000 would cure it?