I have used both Klett and dubro hinges, they boke the nylon part, the pin was intact.

No CA, they were all epoxied in. I cut the slot, test fitted the hinge, removed the hinge and used CA hinge material to apply epoxy into the hinge slot, then wiped it down with alchohol to clean excess epoxy, then pushed the hinge into the slot. This is my procedure to install hinges. Works great on all other airplanes.

I have been thinking I may have a vibration problem, and may try installing flying wires on the tail feathers and see if that helps.