I’m glad you saw the light 
and made the investment, now to sit back and watch your fellow hikers struggle to boil some water in windy conditions 
Although the mixtures on the cheaper canisters are not stated by ratio, they all contain normal butane (N-Butane). As I mentioned in my post, Iso-Butane found in the more expensive canisters are far superior in colder conditions. But we don’t necessarily experience these conditions locally, as you mentioned and therefore the cheaper canisters will work just fine.
Inverting the gas canister actually feeds the stove system with liquid fuel, which is evaporated to a gaseous phase with means of a pre-heater and then ignited. This eliminates the issue of vapor pressure at lower temperatures. This same concept is used on liquid fuel stoves such as the MSR Whisperlite and Coleman Feather, but you need to provide artificial pressure to the canister with means of a pump, to feed liquid to the pre-heater. This is done by the gas pocket trapped behind the liquid, in an inverted gas cylinder, hence why you don’t need a pump.
My opinion is that there is incomplete vaporization of the liquid by the pre-heater on the cheaper canisters and some liquid makes it to the burners. It could be that lower quality propane/N-butane is used for the cheaper canisters.
Jetboil actually makes an inverted stove as well, called the Jetboil Joule, but it seems to be quite large and bulky.