What I would really like to see is a thrust attenuator similar to the unit on the old Air Force T-37 Tweety Bird. Same problem as our model turbines, lots of residual thrust at idle. With the T-37 the solution was to just extend a panel right smack into the exhaust of the turbine at idle, effectively reducing the thrust to zero.

It would be very easy to turn the same attenuator into a thrust reverser by simply making it into a two-piece clam shell "bucket" similar to the unit used on a DC-9.

I believe that on an airliner reverse thrust is achieved when the throttles are brought back past the idle detents. How this would be done with model jets is a good question but something worth thinking about.