On Jun 9, 9:15*am, Stealth Pilot
I tried setting everything up in balance then held my feet still on
the rudders, hands off everything else. the aircraft flew with slight
deviations in almost straight and level flight for 10 minutes or so.
It showed no tendency toward instability which I must say surprised
me.

The problem is that while you may think you held your feet still on
the rudders, it is almost impossible to do. You will instinctively
pick up a dropping wing with rudder. Prove it to yourself - hold the
rudders still the same way you did before - but with your eyes
closed. The airplane will dive off just the same as if your feet were
off the rudders. Just don't do it for too long.

Michael