I added a tutorial for how to add a controlled vocabulary field. As part of that, I have a section at the end that explains how to make the controlled vocabulary selector start with the controlled vocabulary setup when the controlled vocabulary selector field was defined. I didn’t push the fix, because I wasn’t sure if you intentionally removed this code.
BTW, the tutorial contains a step requiring direct manipulation of database tables to connect the attribute loop field to the subloop element. If there is a way to accomplish this through the interface, that would be excellent information to have.