In the last 17 years or so I've only had an issue with 1 Fanatic board, 1 Exocet and 1 AHD. With the Fanatic they twisted then stayed put, so I just left them. The Exocet had a different pad construction/material to my other Exocets, and after I had retightened the screw every session for about 6 times they were ok. Same thing happened to a French mag when they had one to test. I think that was down to the pad compressing when the screw was first tightened, then got compressed a little more in use, so the straps twisted. Same with the AHD, that came with just a washer under the screw which I replaced with a metal tab as below. I've not had an issue with a Goya, Quatro & AV which I have recently had, and they have a metal tab as below. The Goya & Quato have a firmer pad (maybe doesnt compress further) than the others, the AV quite a soft pad, so thats a bit odd. I didnt put the screws in the AV myself, so maybe whoever did really tightened them up tight to start with and they compressed the pad to the max. All the screws seem the same pitch and diameter, except the AHD which were narrower at the tip.
A friend had a new Pyro where the straps came loose, not seen him recently to see if his issue has gone away.