This insert by archeopterix on Thingiverse is great and fits perfectly. I only added some extra body where the tabs were added and would end up needing supports anyway.

I printed in PETG with 0.4mm layers on a 0.6mm nozzle. Add supports to the overhangs for the bolt holes and tabs, or use the project file (rotated to fit on a CORE One, infill direction modified, supports added).

To create the clearance, move the saw fully back to the fence, plunge to full depth, then slowly but firmly slide towards you. This will use the downward stroke of the blade to create a clean edge over most of the length of the insert.