TA is probably perfect, really. You get the TA Jellyfin plugin , mount TA's library directory as read-only in Jellyfin, and add that mount as a "Shows" library with TA as the sole metadata provider. Channels become "Show" names and "Seasons" are the upload year. One-way or bi-directional watch progress between JF and TA. I don't use the feature but I think it supports some sort of organizing by YouTube playlist these days too, maybe as "Collections."

The only issue I've had is JF seems to do some built-in stuff when it comes to filling in metadata based on file names. Occasionally an "S0" or "E12", as examples, will erroneously put a video into "Specials" (Season 0) or give an "Episode 12" where there shouldn't be if those or similar substrings are in the Video ID (which is also the filename). My hackish solution, for a while, was a script that ran a sqlite command against the Jellyfin DB to find any videos in the YouTube library with not null episode numbers and set them to null, and also set unexpected seasons to the year of the video's upload.

I had it automated to run right after my scheduled TA downloads completed but it felt a bit wrong doing that on live DB. So now I just periodically run the query, sans the updating, then fix the metadata from within JF's UI if there are any query results. I could see that being a little irksome, and beyond what non-hobbyists could figure out, but it's honestly a small price for me when it means I have all my archived YouTube content organized, with descriptions and thumbnails, with no other real work on my part.