I’m going to mark this thread as resolved with my own workaround but I still think this is a bug in the library and should be addressed. Using the init hook does not solve the issue it only suppresses the notice and actually returns the wrong return type!
To conclude, in my opinion:
ACF should either drop support for get_value by name or make acf_get_reference also look in the local store to resolve name -> key mapping instead of only relying on the DB or internal cache.
