As many here know, stock Convoy MCPCB screws are pretty bad because their small head is barely bigger than MCPCB holes, and countersunk type makes it even worse.
So thanks to the BLF member Sirius9, who asked me about hole diameter of my DTP pcbs,I accidentally found much better screws (which I had in stock for some other purposes):
They are M2.5x6mm screws with very thin flat head usually used for laptops etc., and they seem to be perfect for tightening MCPCBs in flashlights too.
They don't have countersunk head so MCPCB doesn't move during tightening and you can center MCPCB more easily. Head is bigger so force on MCPCB is larger, and everything feels much more reliable.
Yes, they are compatible. I just opened stock Convoy L6 and it uses the same small screws as C8, they just barely hold MCPCB because you can actually see whole edge of pcb hole,I guess reflector pressure actually makes more pressure than screws. Replaced screws with black ones from OP,they fit nicely.
I think Convoy use same small screws for all lights with 20mm MCPCB and those are C8,M1,M2,L2,L6?