multri's are much different than getting a single 40 in snug and trim.. IMHO, it's worth getting the 40 in so it isn't hanging low and almost straight vertical. Nor is it terribly difficult to get a single 40 snug and trim.
Less drag, less banging the 40 and the reg on it around and less chance of it getting hung up on something...esp is ow wreck environment.
Cave?? LOL, could care less how a 40 is slung, it's getting left at the entrance, close to and I normally hand carry it and dump it off. When I deco i will clip the top , I may (or most likely not) clip the bottom off...
I had 4 AL80's, 1 steel 72, 1 AL40, side-mounted 108's, a scooter, and my CCR. And a partridge in a pear tree.