I built three Mini Guineas. One for myself and one with each of my sons.
Ours also had lemming tendencies, but mostly due to the failure prone TowerPro 5g servos from ValueHobby that we used. Never use those! Each Mini Guinea uses five servos, so out of fifteen servos, we had four go bad within the first few flights. My sons rudder servo went out before the first flight. I had one aileron servo go out on my other sons and one on mine, both causing crashes. Lastly, my sons cargo drop servo has intermittent failures. It was an exciting day when we maidened all three. 😂
After resolving that, they fly pretty well, although twitchier than you would expect with the recommended throw and expo rates. Even low throw is too much, particularly on the ailerons. I would guess that about half the recommended low throw rates and maybe 40% expo would work well. I’m trying that next time we fly.
The other issue we had was the front landing gear. On any moderately hard landing, the paint sticks securing the front landing gear break loose. I just designed a 3d printed insert that will slide into the pocket above the landing gear that will replace the paint sticks. It will have about 5x the surface area for gluing to the foam. I’ll post plans for that when I’m done.
One other comment is that the replaceable nose is wonderful. It acts as a crumple zone and it’s relatively effective! I had nose down crashes with two of my planes and was amazed that the nose was a complete loss, but the rest of the plane had barely a scratch. Genius!