If you're thinking about releasing a new kind of dice bag, let me say that the one thing that bugs me about the bags I've owned is the drawstring.
Sometimes they break, sometimes they become un-knotted and get pulled out...sometimes I simply don't tie the bag closed well enough.
OR I overfill it.
If I were to redesign a dice bag, I'd start by using a heavier-duty drawstring, possibly adding a little elastic, kind of like a good pair of sweats.
I might even go for some kind of slide-locking lanyard construction- you slide the plug up to close it, tie a simple knot, and the thing is sealed in 3 seconds. Untie the knot and slide the plug away, and you're ready to game.
I also might make them flat-bottomed...especially with some kind of water-resistant vinyl. (Think of the bottom of a kid's footie pajamas.)