yeah I've considered doing a blog post about that setup style, i.e. the interplay of shadow-cljs.edn, deps.edn, .dir-locals.el and user.clj. The things is that this is not actually the recommended setup (or I assume it's not, as in not recommended by the CIDER or shadow people). When you start your REPL you can choose if it should use deps.edn or shadow-cljs.edn. This setup is necessary if you choose deps.edn, but you can also choose shadow-cljs.edn, and it'll still pull in what's in deps.edn, but the process will boot via shadow-cljs instead of via clojure.

I prefer to stick to booting via clojure, makes it easier for me to understand what's going on. But it means I do a bunch of wiring myself that shadow and cider otherwise take care of.