In thinking about it the third mode I was just talking about adding is really almost the same as the rudder mode. In rudder controlled mode when the throttle is below the 1/5 point you can control the throttles of each engine with rudder input. i.e. full left rudder if left engine idle right engine full power. Half right rudder is right engine at idle left engine at half throttle. Once the stick is advanced above the 1/5 point this feature is disabled and the engines run in sync based on throttle stick. would this meet your need or would you need the three position switch control?

The other feature I am looking for input on is the engine problem recoverery. I had a P-38 that would snap if an engine failed. I had to immediately cut the power if an engine started sagging or quit. That is really what got me thinking about this and eventually build it.

Obviously, if either engine has a problem the fast engine is throttled back to match it (upto the idle point in case of a dead engine). You can then regain control of the idling engine by pulling the stick back to idle for a second and then you have throttle control again. Does this sound like the right approach?