I think the G scale guys have it made, as the ones that go battery power don't have to care what system controls their trains.
Air Wire is RC style with DCC like code, with battery in tender to power everything it is like Lion Chief other than you can control multiple trains with same hand held.
Others install the guts of a TIU in the tender with output wired into the PS-2 board, another car carries the battery pack that powers the TIU. The DCS remote controls the engine.
I don't have a G layout so when I work on these engine I do my final test on the kitchen tile floor. Run the engine threw its paces on the floor.
When they are out doors on there non powered track each operator brings his own system and off they go. This technology is out there, you just need install it. The air wire is compatible with all the standard off the shelf sounds systems. You want the manufacture to do it for you, they don't want to, hence all these small business that fill the niche. Do some research on it. The boards are getting smaller and smaller and the batteries more powerful. G
