Summary

On my Bosch RA1181 router table, the inset rings (red hole caps) are not flush with the table top. They are low by about 0.4mm. So a created a ring shim that installs nicely on the back of the insert rings. I made it 0.4mm thick but you can adjust the Z axis in the slicer to work best on your table.
Printed it with 0.1mm layer height and in prints in a minute or two.

Print Settings

Printer Brand: 

Bambu Lab

Printer:                      

P1S

Supports: 

No

Resolution:                      

0.08mm

Filament:

Ender PLA                Grey