Manufacturers try really hard to stop their proprietary software from getting out into the world, because when it does this is exactly what happens.

Case in point: I have a $35 phone app that lets me change software configurations on my BMW, and it is great. Can’t change anything related to engine, aftertreatment, or safety though…which is a good thing.

Propane is way less energy dense per volume than diesel, so it isn’t feasible for long-haul trucking. CNG/LNG is more energy dense than propane, but still nowhere near that of diesel fuel, which is why you see it in busses and garbage trucks. I know a few massive fleets (UPS comes to mind) that use CNG for some of their local routes, but that is probably more for the “green” optics than anything else.