The big advantage of the bluetooth (or similar) is in theory you can have it under complete computer control ... if you like that sort of thing. The big disadvantage? You'll never be in sync with the master engine...
But perhaps you can get close.
So vague-ish ideas, but untried ... if you are using DCS, you can use Mark Divecchios RTC program (or pieces of it) to possibly continuously poll the engines state and get some sense of what it is doing -- or if you were just using it (RTC) as the control -- you would in theory know what the engine has been commanded to do -- and therefore any slave sound systems could be put into the right state by the computer mirroring the master engine ...
With Lionel LCS you could maybe watch the bus for commands, do something similar... maybe. The sensor track would send a status packet so to speak but I don't think (well i'm fairly sure but this is from memory) -- that it has the complete state of the engine that's run over it...
Still, such info might help somehow also...
