Speaking if triangular drums, there was a company in the US who was experimenting with them, although not with the sharp angles of the Deltadrum (what's that flower you've got on? hahahaha) The premise was that you would alternate the direction of every other tom, so they sort of nested against each other, and you could fit more toms in a somewhat smaller space.
As you probably know by their absence in the marketplace, they went nowhere.
R.O.C.K. Drums currently makes unusually-shaped drums as well, and they're not having much luck, either.
Bermuda