Somewhere in the McGizmo forum, Don already explained about "his" screws, which may be the same, I don't know...
Most didn't work for him either, they must have extremely low tolerances for ti and that's just not the case with stock screws. As Don makes a few lights more, he has his screws made in extra batches, IIRC they are not especially made for him, but hand-picked.
I'd be OK with ss screws everywhere, I doubt I'd ever notice a difference whatsoever, I normally don't use the clips, on a ti light they are a must for the optic though, nothing's like a nice clip to dress a light and the one of the EDC-SST50 is indeed very nice (and tough if you need it) and worth the extra money!
The person at Lunsford that makes the screws told me he specially makes the screws for Don.
Mac