The outdoor product I really, really want to see.
Propane is widely available and much, much cheaper than canister fuel. The problem is that propane is stored at much higher pressure (usually around 50psi) so it typically comes in quite a hefty steel container. That high pressure is a feature, though since a small hiking stove would run longer and much better in lower temperatures than with typical propane/butane fuels.
I see no reason that a pocket rocket or similar stove would not run on straight propane rather than a butane/propane mix.
The problem is that canister. I’ve seen oxygen bottles used for climbing mt. everest that were aluminum reinforced with kevlar. Chances are the oxygen is stored at even higher pressure than 50psi (I don’t know this) and I suspect that a variant of that design would produce a reasonably light canister that could hold straight propane.
Now if you sell it with a regulator you can fill up your canister anyplace that sells propane. Given that I go through a hundred bucks or so of canisters every year, you could charge me quite a bit for this whole gadget and I’d joyfully pay it.