Fred, At this point there is no way to run a Command engine in command while running conventional sounds in command too. You are now talking about combining 2 command systems in one engine and using the TMCC to run the engine and DCC to run sounds. Basically 2 different remotes in your hand.
If Jon Z markets the translator, which would take TMCC command signals for sounds from the R2LC or even a Legacy R4LC and have it converted to provide the appropriate DC offsets to trigger conventional sounds, you can get half way there. The only other issue is speed related sounds, which maybe able to be run off the motor, as long as it doesn't mess with Speed control. Tach driven motor control might not mind, while ERR Back EMF might not like a load on the motor (Based on Jon Z comments).
Your also going to have to deal with 4 motors on an ERR board. Not sure if it is meant for that. Does it take 2 ERR board or a DCDR slaved? Not sure.
G
