Anyone who’s stripped the threads of their aluminum/metal yoyo, I can fix it, so long as there’s enough metal to support a bigger diameter hole. I make EVERY 3YO3 plastic yoyo by hand, start to finish, so I know yoyos inside & out. I’ve done ~20 re-taps, all with great success, many on very high end stuff like YYR, etc.
Here’s a picture of a YYR that was originally an M4 axle, but has been re-done to M5.
And above is the original axle (with burs caused from axle removal with pliers) next to the re-made axle I did on the lathe (only cut to length & faced/chamfered on the lathe).
If you’re interested, I generally try for $20 shipped for this service.