In case of vim-plug:
Plug 'nimaai/vim-shadow-cljs'
From within a cljs file call :ConnectCljsRepl to setup the repl connection. It looks for a .shadow-cljs/nrepl.port file.
Afterwards, switching between clj and cljs files automatically switches the respective conjure client states and thus keeping 2 repl connections open in parallel.
It reads the build value from shadow-cljs.edn file under :builds. It takes the first key.