Unless we frag a 'force QNH', we switch to 29.92 at FL180 even in the NTTR as we're in US airspace.

Hypothetical, at a given day standard setting will read 1,540ft at the Nellis RWY 03 threshold so we adjust our altimeter to read 1,840ft at the 03 threshold (or S-E EOR for that matter).

If FL180 is the transition altitude and I switch to standard upon reaching it, I have only 200ft seperation with somebody who hasn't transitioned yet and is flying at 17,500ft. Is there something like a minimum altitude above FL180 you have to fly in order to ensure vertical deconfliction? Or is that something we should frag and adjust to on a case-by-case basis?