CloudRendererMixin::internalCloudRender copies a large chunk of code from WorldRenderer::renderClouds. For maintainability and copyright reasons this should be avoided

Agree with this, though to do so would need a major refactoring. I would be open to a PR having a more maintainable system however.

Slated for PL b1.7

Pushing this back- I'm not smart enough to refactor this but we make very small changes that would still require replacing the code with a mixin because of the data that we modify. Tried some workarounds but ended up infinitely looping because we mixin directly to the render clouds method and then would need to call it ourselves to not duplicate code