Pretty cool Jonce. Is that Phifertex? I sewed up a prototype myself for Rocket out of some Weathermax fabric.  Not to worry, I have no intention of mass producing them!  I think it's a pretty nice idea, and like the look of what you've done.  Having some ventilation may be a good thing too.  Getting a fastner that's not going to come loose would certainly be key.  Could you elaborate a bit more on what "hard action snaps" are?  I assume just a stronger than normal snap? I was thinking something like a common sense fastner would be nice there.  A one way snap may work, but not sure you would be able to rotate the fabric to undo them.

Troy