The spacer that came with my faucet was just a touch too long. The screw reached, but just barely and the faucet would pop off constantly. Buying a longer screw would be too easy, so I made a new spacer. I found someone had already made a model for a stopper which was close enough dimension-wise, so I quickly edited it to replicate the full spacer.

The original was 35mm tall, not counting the “teeth.” Mine is 30.

TinkerCAD link. Just change the dimensions of the round piece to whatever you need and move the teeth to match.

Printed on a Bambu X1C. Prototype was done in PLA with extra draft mode (.28mm with a .4mm nozzle). That was probably fine, but I didn't want to risk breakage so I printed the final version in strength mode (.20mm) with PETG-CF.