I got it figured out.
So yes, I did go with your suggestion to create the document attachment metabox using ACF, I then exported the code and dropped it into my functions.php so I could make some small modifications.
This was my first attempt to modify the UI for wordpress and yes I struggled because my php and js is very weak to put it politely. But I didn’t give up and now I have a nice little user interface that allows one of three field inputs to display, depending on the users desired outcome.
We all have to walk before we can learn to run, this was me learning how to crawl. lol.
