We do have the Traditional setting for Composer but that's really a different thing. Lots of PD songs have unknown composers but with many the composer is known.

Thoughts?

This website is very useful .
https://rockytopconcert.weebly.com/w---pd-songs.html

With the crackdown in recent years by the RIAA of businesses that have music it's useful to be able to assure the owner you will only play PD music. Which is quite doable with folk, classical and bluegrass musicians.