Here's an idea...why not set the upper limit based on how much FPS you actually NEED rather than based on the 'average pain tolerance' of those posting? Why cause more pain if it's unnessary?
Possibly have a couple tester games. Talk to some of the players using different FPSs (ranging 300-350, etc). After they've played sufficiently, ask them if they can recall any instance where they felt they NEEDED a little extra FPS/Range to make the shot. I think base it off of that as the CQB facilities will range as will opinions here.
I've only played a handfull of indoor CQB games but I used a stock TM (~270 fps) and and I didn't have much trouble shooting the entire length of the course (accuratly) - which was just over 100ft.
Having guns shooting hotter than they need to be is pointless besides causing more pain and potential for hard feelings, IMO. I would also feel a lot better playing at a facility where I know the FPS limit is based off what the average player NEEDS rather than getting lit up by some body who doesn't care how much pain they inflict on someone else and push their guns to the limit simply because they can.
I think most people prefer to not wear full face masks for comfort and finding something they can aim properly with at the same. I know I'll probably never wear one unless I feel the FPS is higher than it needs to be - I'll sacrifice a little bit of (necessary!) pain for comfort.
Ronin 49 Team Member