The best HACS addon by far in my opinion has been the Node-Red companion add on that makes combining HA with NR significantly easier and more powerful.
I do almost all of my automation in NR flows and HA is mainly API connector and dashboard frontend.
I automated this with FileFlows.
New media automatically has Audio tracks sorted with the best track (English, most channels, highest bitrate) set to index0 and set as default and a basic stereo AAC track added for compatibility if there isn’t already one in the file. superfluous tracks are removed. Subtitles are also cleared out if there are extras too.
I also have Fileflows handle a light compression pass on files that are more than 6 months old for archival, in certain video libraries where I don’t need perfect copies stored.
Most of the files you get from private and public trackers will be same ones you can get via Usenet so it’s pretty much the same everywhere, filtering your *Arrs to prioritise certain release groups helps when you know specific shows or genres are better supplied by a certain group.