I printed this with thick walls (~1.8 mm) and light infill (5% gyroid) using PETG.

~0.6 mm bottom layer

~0.9 mm top layer

Also made a spacer to fill the gap back to where the mounting screws attach so it's less likely to deflect under the tension of the screws, which broke the original escutcheon. Scale length-wise to whatever length you need. You can print the spacer laying down. You may want to glue it on the back and/or make sure that they kind of hold on to the screws so you don't drop like 5 of them in the wall like I did.