I think its actually might be Cordura, don't know if it makes a difference as I think its still nylon based.
It's not a molle pouch, its one of their chest rigs styled after one of the classic AK rigs. I stuffed it w/ some cut up pool noodles and soaked the pouches with some warm water and stuffed a spacer between the two halves of the pool noodle to stretch it out some more. Don't know if it'd work as you kinda confirmed nylon not stretching but hopefully it does.
Its this rig here:
I actually have problems stuffing mags into two of the pouches, so haven't really got to the part where I need to remove them lol. Two of the pouches (the ones to the left and right of the center pouch) seem to be a bit on the tighter side and I haven't been able to get two G3 mags in there yet without a lot of work.
*update*
Have successfully stretched out the pouches with the "warm water & stuff the pouches with stuff to stretch it" technique. They can fit 2 of the G3 magazines with relative ease now (except for one pouch, still need to work on that), I've repeated the process again and stuffed a few pieces of folded up cardboard between the pool noodles in hopes of stretching it out a bit more. With luck, I'll be able to fit the magazines and thin kydex insert inside the pouch.