not-much-io: Switching the dropdown doesn’t actually start a CLJS REPL, that’s just there so you can indicate to Cursive what the type of the current REPL actually is if it doesn’t autodetect it correctly.
not-much-io: You’ll still have to actually start the CLJS REPL following the quickstart or using an nREPL implementation of some kind.
For the very last gif in: https://cursiveclojure.com/userguide/editing.html , what do I have to press to get that menu pop up?