[Hectic]

Yeah i thnk its a cool concept.
The fact its for p90 mags makes it a bit bulky,
but say it was for m4 mags. It could be about the size of a tripple double mag pouch (one that holds six double stacked)
but it could hold 8 or 10 mags in the same space (sort of) it would stick out a bit further but could be a bit narrower so you (well at least i with my small frame) could wear two on the front of my rig one situated with the opening in the front center and one on the off hand side (left for me)
facing downwards (sort of over the hip) then i could use that one if i was prone blocking the front center one or upright once the front center one was empty.
I think it could use some kind of stopper between the last mag and the first empty one so once all the mags inside are empty if you try n grab one there is nothing to grab.
Also it would have to be somewhat flexable as on my small frame to wear two id have to have it curved (i got a 30ish waist so you have an idea what i mean)
For sure for urban/cqb this thing would be awesome as most wouldnt need snything more then baisic gear a gun and as much ammo as they could carry. For out in the field when a patroll pac is needed they would have to me more the size and shape of existing pouches just with a lil more capacity in a simaler space and the ability to be mounted in a simaler fashion.