The plasma cutter will cutter will do 3/4+ mild steel. maybe an inch. Edge start so you would need to pre drill a hole… The cnc is in a questionable state. There are some intermittent faults. I am not sure how you would align it anyway without sacrificing a sheet of metal to cut a matching circle and dropping the cover in the resulting hole.
The hand torch should work. I have never hand cut with it so I can’t say what it would be like.
I would look on the wiki to verify cut speeds and thickness. I thought it is a hypertherm 65.
Doing some test cuts in the outer ring would let you know what it would be like. A lasy Susan setup with a clamp on the torch head should produce a nice circle. You would just need to match the speed of cut.