Yeah, I believe 347v wiring devices even use a different hole spacing to prevent them from being used in the wrong junction boxes. The boxes are similar to the ones used with 120/277v but the single gang boxes are wider than standard boxes and the multi gang boxes are required to have dividers between each device. Interestingly 347v receptacles are also made too although aside from high bay lighting, I'm not sure what would use them.
I also prefer the 277v rated "spec grade" switches compared to the standard residential grade ones. They seem better built and I think have a stronger spring which makes the switch snap open/closed quicker compared to residential grade. I also prefer the "spec grade" receptacles over the residential grade ones too. They have dual wiper contacts which seem to last longer and grip plugs better compared to standard outlet.
I recently got hold of a pretty early electronic T8 ballast that had a date code of March 1993. That's pretty early for electronic IMO. It's this
Osram Quicktronic QT-2x32/120 IS. It wires up similarly to a modern electronic instant start T8 ballast but has it's own ground wire instead of being grounded through the fixture. The case is also the same size as a magnetic ballast too. It's also 120v only like most older electronic ballasts.