Hey Thommy, This is as clean as I could manage getting my world. https://drive.google.com/file/d/1snaKn8LxyDSEoQ_FGx1cRl7W-bfrFx7v/view?usp=sharing Thanks for your help!
I have a world from 1.16 that is throwing identical warnings as well. No issues on 1.16, however on 1.17 it sends this warning, but otherwise appears to run correctly. No apparent lag or other issues.
At this point I've lost any hope Mojang is interested in resolving this and I'm honestly very disappointed that such a critical issue has been neglected and left to the community to make guesswork fixes for.