I would think it would be a problem when you fall off and you're not wearing your life jacket, but that's just me.
(Just like seat belts, they only work if you wear them.)
Last weekend... A couple younger sailors took a Wave out to play.. One was less experienced the other has plenty... The boat popped up and main sheet was dropped.. It came back down a bit hard from flying I guess and both of them fell off and into the lake.. The boat quickly sailed away with their life jackets on board.. They were quite some distance from shore and the less experienced one was even wearing pants.. (which he took off, but didn't know how to make them into flotation.)
On shore some time had passed before we noticed we hadn't seen the boat.... and we just figured we would check up on them before loading Race committee boats on the trailer... Sure enough there was the Wave being pulled by a ski boat flogging the sails.. The kids said several boats went right by them in the middle of the lake thinking they were just playing before the boat full of drunks stopped to pick them up and help rescue the boat..
The wave was probably 1/2 mile or more away hung up in tree stumps...
That could have ended very badly..
On a practical matter, I think you'll find that it's hard to keep things in a open mesh bag in any kind of seaway. A bag on top of the trampoline works much better. A paddle can be stashed under the center tramp lacing.
EXTRA life jackets clip under the tramp in the lacing pretty easy... I have a couple bags which clip under the tramp along the center lacing, and I find that works quite well.. Maybe I am just a dummy... But every time I try and tie up anything on top of the tramp, the jib or even the main sheet ends up fouled up in it... I see people with soft coolers and all kinds of junk... It never seems to work out for me..