This is the first step down the road of using tags and filters to create a personalized view of your discussions.
We don't have tags or filters right now, and Flow isn't deployed on enough article pages or namespaces for those to be useful yet.
One useful thing that we could build now is a special page that shows you a feed of conversations that you're currently subscribed to, from any Flow board on the wiki. It can work just like a regular Flow board, with a table of contents and sorting options.
This would only be visible to the user, in the same way that Special:Watchlist works.
I'm not sure about what to call it. Related examples are Special:Watchlist and Special:Contributions.
Brainstorming -- Special:Topics, Special:Discussions.
It would be good to have a spec & mockups to show at Wikimania.
T107207: Cross-wiki personal feed
T101930: I want to watchlist the intersection between two pages
T94798: Flow: Ability to aggregate topics on more than one board based on some criteria
T90069: Tags for topics
T88107: Ensure RSS feeds of SMW queries against Flow topics embed and link something meaningful (Translatewiki)