We've just published a new version of the thymeleaf-extras-java8time, 3.0.1.RELEASE (for Thymeleaf 3.0.x).
These is a maintenance version that should be usable as drop-in replacement of the previous 3.0.0.RELEASE.
Specifically, the new version improves the way null-safety is applied at the #temporals utility object so that it behaves more consistently with many other utility objects in the Thymeleaf core.
See it at the project's page on GitHub:
https://github.com/thymeleaf/thymeleaf-extras-java8timeRegards,
Daniel