We recently introduced a defcustom allowing to choose a fixed option instead of sending it to both repls - may be handy

But no, I don't think we have reader-conditional level detection. We have reader-conditional-parsing code in clj-refactor.el (including for partially written stuff) we could reuse it

I mean detecting by where you are inside the fiel

what’s the defcustom to control where it goes to called?

https://docs.cider.mx/cider/cljs/up_and_running.html#working-with-cljc-files cider-clojurec-eval-destination, good to set in .dir-locals.el For the other approach, feel free to create an issue, probably it deserves some discussion for edge cases

and that’s global or per-file?

I’d often want to change this for the buffer I’m working on

Global, however you can use setq-local 👌