I’m installing a new wood floor in the townhouse that I’m renovating. Initially, I used a hole saw to make some rough openings for the heating system. However, they were crude and temporary. Using a template and several routers gave me a professional cut. See photos below.

Temporary openings for the heating system.
I made a template using 1/4″ MDF.
My initial cut was done using a small router, as it was more maneuverable.
A bigger router did the final cut.
A perfect cut.