You will discover there is no need to turn off in flight. Tail waggle under 'G' at higher speeds is an indication that the gain is a little high, it is not a big issue, its simply a matter of adjusting a little before the next flight. If the gain were adjustable in flight I suspect this would be very counter productive as it would be most difficult to do.

For stabilization of runway excursions I beleve all these units: cheap units with pizzo sensor, expensive units with pizzo sensor or antiquated ones with mechanical motor driven flywheel sensor will do the job.

I,ve also used the israli built BTA-1 gyro built for RC fixed wing use I think about twelve or thirteen years ago Even it could handle the job its problem was it was large and very heavy requiring its own heavy power source.

My P-38s use 4.8v but there is only one reason for their existance and that is is warbird pylon racing, I suspect they see speeds and loading your giant scale will never see.
That cheapy gyro does a great job in buying a few extra seconds to identify and react on an engine out. Of course that is not your problem however it does a fantastic job of stabilizing the typical runway waltz, I think thats what you,ve been talking about all the time.

Other folks are also starting to use the simple gyros in the warbird racing venue as some of these deliberately overpowered airplanes with lousy scale landing gear geometry are frequently lost in T/o excursions before the racing even starts. You know what? it works.

It would seem to me as many others you are over engineering the simple device to death and going nowhere as another poster suggested just get a cheapy of any brand and try it. Its certainly not going to crash your airplane. Otherwise you will never know or benefit.

One last thought is yes it will enormously help in stabile T/o runs but it will not help in your formation flying efforts that you hinted at. The problem there is not in yaw stabilization but pilot induced excursions in pitch and roll aggrivated by poor pilot visual perception. As always formation flight and I mean the real thing is almost the holy grail of RC flight. I assure you formation flight in full scale aircraft is relatively easy when compared to RC.


Just go for it and enjoy

John