Fwiw, I made something similar, but it targets an ancient version of OS X. It's theoretically possible it works on modern macOS too, but I haven't tested it.

https://github.com/Wowfunhappy/media-subscriptions-prefpane

I've been using a version of this for five years, although until recently the PrefPane was built via janky Applescript. I rewrote it in proper Objective-C last summer.