Two things: first, I've never completed Final Doom on UV, only on HMP.
Also, even though I'm the guy who goes on and on about Maximum Doom because I played through most of it, I've never actually given the Master Levels a try - even though I really like Jim Flynn and the other guy who's got a bunch of Max Doom maps. I could say in my defence that I've WATCHED a bunch of walkthroughs of those levels, but it is still a shameful confusing thing to have to admit.