I've seen one or two people say they were going to try it, but they never presented a project/how to/list of issues they had, you know, the useful stuff. It's probably *possible* to extend RenderServer without heavy updates to the Editor, but I'm not sure what minimum feature set is.

They've exposed some elements of the render pipleline, but replacements-as-plugins are still floating around the proposal space for Godot. You're kind of stuck completely forking and building it from scratch.
github.com/godotengine/...

MTV had a pretty big hand in my taste in media, with Aeon Flux, Liquid Television, Oddities, etc.

It's such a shame no one seems to have any interest in reviving it.