Very cool project! If you build the next one more scale, make sure that you have a 3 axis gyro. With flaps down on a normal landing approach, I seem to remember that I didn’t land with more than 20 degrees of flaps. At slow speed, the spoilers were not very effective. Flaps didn’t move or act as ailerons. On final with a little bit of wind, you would have to move the yoke 90 degrees from center in both directions just to keep it stable. At high speeds, the spoilers were very effective. Flew them in the early 80’s. Was the fastest turboprop at that time, maybe still is, but I don’t know. A lot of guys killed in them, due to poor training. It didn’t need a Type Rating.
For reliability, I am assuming that you are using electric engines?

Did you used to own, pilot or work on them? Not too many people know about the Mu-2.