Hi @sovamind,
Thanks for your interest in this. ListenBrainz support has been discussed internally with the Plex team, and isn’t something they’re able to implement at this time.
I understand using webhooks isn’t the perfect solution, but for what it’s worth, the source code of the site is available at GitHub for anyone interested in reviewing what’s happening behind the scenes, and I’ve run it past the MetaBrainz team for their approval as well.
With regards to plugins, that was my first thought also, however plugins aren’t well supported by Plex any more, so I wanted to do this as close to “the proper way” as possible.
Just a side note, @TeknoJunky from that thread you linked to is a user of this solution too!
Anyway, let me know if you have any other questions or issues!
