It doesn't actually make sense to fork Elm. There are pretty good general-purpose languages already which offer a superset of Elm's (the language) functionality. I think all of them already have Elm-like implementations available as libraries. In fact there's at least one migration tool that helps convert away from Elm: https://github.com/darklang/philip2

Choosing to hard-fork Elm and create lots of internet drama just doesn't make sense compared to moving to one of the above.