Tuner screws - do they wear out?
My 2nd PRS, a DGT, has the phase III tuners. Though I only got one extra screw with the case candy (should there have been more?), do they ever wear out, or just more commonly lost in black-hole workbenches or couch cushions while changing strings?
Longtime lurker, seldom poster,
They won't wear out, they will only wear if you somehow manage to cross thread one, but being the shape that they are that is extremely difficult to do (and you'd have to be very ham fisted).
The spare one is in case you lose one, but even that is difficult. You don't need to remove the screw to change strings, just unscrew it enough the get the new string back in there.
I've lost more spare screws than I've lost screws from the guitar itself... (one)