One of the best features of the Plex App for users with large private music collections is the ability to search by folder., since many files in such collections have limited metadata and can’t be searched by Artist, Album or Genre - they show as Unknown. Unfortunately, Sonos can’t index libraries with >60,000 files, which is my situation. And casting to Sonos from Plex is just not a smooth operation, as many users have complained about.
The Sonos forum indicates that the ability to search by folder would need to be implemented by Plex. I’ve seen it come up many times in the Plex forum and it seems like an easy solution to implement, but it seems to get ignored.
There’s already an existing suggestion discussing an option to support folder-view for Sonos. I suggest you comment/vote in that thread in order to help us avoid distracting or cannibalizing votes. Unless I’m missing some unique aspect of your suggestion I’ll close this thread as a duplicate.