I have both this mod and Survival Tools Reborn. I recently acquired some Glitterworld Multitools from Survival Tools, and I've noticed my colonists grabbing full HP Multitools and trying repeatedly, and futilely, to repair them. They eventually seem to "finish" repairing and return the multitool to the stockpile, only for another pawn to come right behind and try to repair it again.

I did some poking around and noticed that there is a separate bill all its own for repairing Multitools at the mending bench, called "repair advanced tool." Unlike the other repair bills, it has no slider for hit points. The "repair basic tool" bill has an HP slider and doesn't have the issue. Not sure if that's actually the cause or just a coincidence.

Screencap for reference:

https://imgur.com/a/75YuMOB