Not the poster you're replying to, but my archiving rig uses my personal fork of "tt-rss" to pull in the RSS feeds for the channels I care about and a script to query the database. That script uses yt-dlp to download the videos and subs, then marks them downloaded in the database. It's a bunch of glue-and-tape scripting code but was easy to hack together in an afternoon. Tweaking yt-dlp to run at a velocity that didn't get my IP address put into "you must login" hell was the most difficult part. The only long-term care-and-feeding has been keeping yt-dlp updated in the face of the arms race.
> Tweaking yt-dlp to run at a velocity that didn't get my IP address put into "you must login" hell was the most difficult part. YouTube is pretty hassle-free in that regard, at least for my IP region.
I have a script that downloads sequentially, and there’s an optional variable interval in between—though I don’t think I’ll actually need that. I once downloaded the entire contents of a YouTube channel that had over 400 GB of audiobooks. After a while, YouTube throttled the speed to 1/2 MB/s—which didn’t bother me, but everything still downloaded successfully. That was already two years ago, though.
A few days ago, I spent two consecutive days nonstop downloading playlists from YouTube Music, but that didn't trigger anything either.