Google, Cloudflare, quad9, QPS

I was curious, even tho ive never had a problem in the past..
I do festival and event wifi, and for years now ive always just handed down public dns servers to the clients so kind of relieve stress off the routers. I have been experimenting with other ideas to do DNS in house, but at the moment I dont have quite have something in place quiet yet.
Also when possible I do get a block of publics and I can source nat networks out of different publics.

But anyways, just wonder if anyone has ever seen anything relating to any of public dns server rate limiting or just blocking dns. Ive read in some places that google does and then I read in others that they dont. Ive seen even on the Cloudflare page that they dont rate limit either. but just wanted to ask out to see if anyone else has seem something like this in the past.

Thank you !!