I’m not quite sure why you’re spending so much time giving me lots of reasons 2-wire systems are bad and don’t work. Fact is that 2-wire systems are in widespread use. The engineering is well understood. They are the preferred solution for large scale systems.
Seems like you’re hung up on wire gauge. Use whatever you want as long as it has the current carrying ability. Personally I run wire in conduit, so other than dampness I don’t sweat mechanical issues. Yes “2-wire” wire works great.
Personally I have no interest in system compatibility since commercial systems are expensive and not attractive for homeowners.
If all the inrush current concerns you mention were legitimate, you’d see something other than a long wire with valve nodes attached. BTW that inrush would be an issue in a “wire per valve” system too…
Ok, I’ll be sure to come back here if I need any help listing all the reasons something can’t be done that has already been done 🙂