Tube Archivist. It’s perfect for that. Your kids don’t even need to know Youtube exists. I just installed it and imported years of downloaded YT videos. The search engine finds anything in milliseconds!

Add another mini PC off of ebay and you are golden. I’m running most of this on a Synology NAS with a much weaker CPU. It is not quick but OK. Unless you want to add much more than this it will be just fine.

I did not know this feature existed. On to creating a separate gmail for my services!