Movie Sets Management Upgrade?

I’ve always manually created movies sets for my library. Since KODI’s set management is rudimentary, I’ve been using XWMM/WIMM. Sadly, the project died about 18 months ago. It still works for Krypton, but I’m sure it will break at some point in the future.

One additional feature would greatly increase KODI’s set management usefulness: The ability to quickly see which movies AREN’T in sets. This could simply be a list in “Manage movie sets” that could be sorted or filtered to show the orphans. Then just click on the movie and add it. It could also be the way movies were moved between sets.

I’m not a programmer so I have no idea how difficult this would be to implement. I also recognize that I’m in the minority of users who prefer custom sets to genre sorting or letting KODI create its own sets. But it would greatly enhance KODI’s usability for me.I have no idea how I would locate orphans if WIMM stops working.