Just poking around the sto-fen site: are you talking about the Omni-bounce, or the two-way bounce? Either way, the omni may be a good investment. I've had situations where the 283 coverage runs out of my 4x5 negs before, and that looks like it would help remedy that problem.
Fastest (and only) lens I own is an f/4.7 135mm. I do enjoy shooting at wide apertures with the camera on certain subjects, but it requires much more attention to focus, which could be troublesome in a high action situation.
Anyways, I'll ask my sister to ask the doctor what he thinks about flashing on her next check-up. Maybe even get a room tour beforehand with the lights on so I can meter and see what I'd be dealing with, then make my decision.
I did a little dry run last night. Once focused I ran through 18 photos with a grafmatic in 1:50 vs 30 seconds with a RF. both paying little no no attention to composition, but blindly shooting as fast as I can has never been something I've been fond of. I also don't think if I strapped my flash on as well that it would be able to keep up with that rate, though maybe if I kept a pack of fresh batteries ready for when the time arrived it could. I'll have to do another run and find out. and if one shot would slip by during the longer grafmatic swap, so be it. Just another trade-off.