Good topic (bump received 
), nice to read and thanks for taking time to describe how you are using Roon (in for me undiscovered ways).
I am still thinking of the best way to organise my library & what suits me best, so I can’t tell much new insights in use.
After writing this down it seems to become more of a list why I don’t go all the way using tags, because of some shortcomings in usability :-).
My current "workflow"
When I listen to “Roon Radio” I am tagging tracks (which means it’s a song I want to hear it again in a specific situation or mood), a dinner for example.
I don’t tag albums, artists, composers, playlist (at the moment).
When we get friends over, I dive into the tags to find suggestions to add to a playlist.
I used to keep the saved playlists in folders (iTunes / Spotify), but in Roon I have only a few.
When I can’t remember an artist name or track name I try to search with tags to find the “forgotten track”.
I hope to find some time in the future to reduce the genres (I now use Roon, but this is to much and not always to my satisfaction).
There are a few things what keeps me cautious (besides lack of time).
In no specific order:
1- Tags are only visible when viewing an album
So when browsing music I need to go the album to see if a track is tagged before.
Even the queue does not provide this information.
Most of the times there are too much clicks (3) needed to add a tag to a track.
2- No intuitive browsing in tags
When more entities are tagged (album, playlist, track, artist) I can see in top how many albums or artists are tagged.
It is not easy to jump quickly to this tagged album, artist or playlist.
Furthermore, I’m sometimes lost when browsing in tags.
For example: in the tag browser I’m in Acoustic (in the header I see “Acoustic”) zoom into the tag Acoustic, I see View All.
When I change the view to Artists, I see 79 Artists (the header changes to Artists). Anthony and the Johnsons is listed here with 17 albums,
though I only have 1 track of him(?) tagged as Acoustic.
When I click NOT acoustic, I see all Artists and Anthony and the Johnsons disappears, though I only have tagged 1 track as Acoustic.
When I go back to the tag Acoustic and choose Tracks, which gives me a complete other view.
The UI change is not coherent to me.
3- Missing boolean options
It’s not always easy to find what I want (show me dinner AND acoustic).
4- A confusing / unclear view when there are lots of tags.
I think hierarchical tags (folders) will solve this:
A set of toplevels i.e. Mood / Tempo / Occasion: drilldown to a sublevel and see Dinner / Party: drilldown to a list of Dinner tracks.
(I’m aware of Bookmarks, but for me it’s not logical to use this and I don’t want a long list of Bookmarks)
5- What has Roon in the pipeline?
6- Last, how will tagging evolve, in other words: will my chosen path and effort work in the future: