Some background: I mostly use Plex via Plexamp to listen to music, and I have my plex account linked to my last.fm to scrobble. I like this as even if I listen offline when away from an internet connection it scrobbles everything when I reconnect, and no matter what device I listen on they all scrobble without any extra work.
Plex already seems to use MusicBrainz for metadata, and are listed as a supporter. It would be nice if ListenBrainz could work as seamless with Plex(And Jellyfin, Emby, etc) as last.fm does. It would be great if you could work with them to get support built in.
That said personally I have so many years of last.fm data, I will likely keep using it along with ListenBrainz now. So I will have to keep importing to update my data. It would be nice if I could link(really just add my last.fm username in my settings and have it remembered) my last.fm account, and then if there was a setting to auto import every few minutes in the background any time I have the website open as I understand the importer runs through the users browser not in the backend. Also I guess that means it would have to account for people who have multiple tabs open maybe?