We use Excel's JavaScript custom functions add-ins for various "sets" of custom functions that user may or may not have access to depending on their job role. Unfortunately, that means we have to hav...
It's possible to do this currently, but it's not officially supported and is a bit temperamental AFAICT (see https://stackoverflow.com/a/73229697/2644016). I found it only works after the task pane in shared runtime has been opened.