I feel your pain regarding ClojureScript.

A few years back there was a 3 month window where I had everything (lein,fighweel, emacs) configured just right, and I could reliably start a Clojure REPL, a Clojure Script REPL connected to a browser window, and switch between them from emacs.

It was really productive, I could work on the backend parts, frontend parts, and effortly switch between REPLS, but then there were some updates and I never got it working without friction again.