Do you mean as a Joplin competitor or something like an alternate client? Or just a "dev" version with a view to merge with the official release?
For example the request to have a "summary" of each note in the notes panel has been requested more than a handful of times and I think that is probably the main thing that people miss (in terms of UI/UX) migrating from Evernote to Joplin.
Otherwise as a standalone "theme" I really like it, ideally with some of the new changes it might be possible to release this (sans anything not supported by the API/CSS etc.) as a plugin theme like the macOS theme - Plugin: 🎨 macOS theme for Joplin