The only small screws i have laying around are from computers, so nothing as low as a 2.5, On mine you cannot get 4 or 5 turns. 3 turns and it falls out. A very sloppy fit also.
I have an M2 0.4 tap and screws for something else and they are too small.
My phones no good on macro, wont focus properly. Silly because teh previous model was brill for macro.
Will have to try the scanner. Thread pitches and cheap items from China always seem to test me, M6, M7 and even an M8 at 0.75 pitch for example. Switches and potentiometers arrived without fixing nuts and these sizes, find suitable nuts was a pain in the whatsit.