Hey Jeremy it was the SP
If you use more flap the elevator loses authority
The stab failure I saw ( I was spotting ) was during a turn when the pilot got disoriented the plane flipped inverted and he pulled full up he had quite a bit of speed and the left stab folded
You have the older kit with the aluminum rod this was a newer kit with a carbon tube
This plane needs to be flown with a little care during high speeds especially in a hard turn , the Peggy as you know is a little heavier but is a brick sh%& house almost indestructible ( LOL)
Ill send you some pics if I get home at a decent time if not tommorrow
Ted