I'm not sure why you think Lisp makes this "emacs" unless you're worried it'll fall flat because most Lisp-interested folks would find emacs more full featured? I'm not sure if a Scheme is particularly different than neovim's Lua. I'll be honest though I'm not sure how deeply Steel is integrated into Helix.
It's not integrated at all right now. It's still sitting in a feature branch unfortunately.
Ah I thought the big branch finally got merged.
Not yet. PR is still open and waiting for someone from the team to review. I suspect this won't be an easy thing.