Just thinking about my limited experience on this: We had a single Comanche in for some check or other.and I noticed an oddity in the leading edge of the stabilator. Had a closer look and it was a dent that had been filled with polyester putty. Bells rang in my memory and I ran a check on the balance. Which was out. The bells were the event that the CAA used to make airtests conducted by CPL's. A PPL owner of a Comanche 250 conducted his own C of A test with some friends to make the weight. He reached the Vne while still in a shallow dive, rather than pulling it up before to hit the number in level flight. The stabilator fluttered at the higher speed due to the imbalence and it removed the whole unit. The a/craft nosed over and the wings failed in negative G.
We had a Zlin 526 in with a private owner. When Neil Williams had a structural failure practicing for the aerobatics championship in a similar a/c and had a wing fold up. We got a phone call the same day to ground the Zlin. The main spars were tested with NDT methods, along with the rear attachments, All OK.
Several French flying clubs used CAP22 aerobatic a/c. After a couple broke up in flight, they found that the G meters had recorded frequent overstressing and it was common on others they looked at. Difficult to see what they thought they were thinking of, if they could see they were overdoing it.