That reminds me, I think I remember reading on the FreeTube page that they recommended using a VPN with it (this was before the current issues with Mullvad); anyone know why? Are FreeTube users in any danger of being hunted down by Sundar Pichai & co.?

Yeah, same here! I have to turn off Mullvad when watching FreeTube which is definitely annoying.

Possibly Odoo . . . ?

https://archive.is/OqKnx

This isn’t really what you’re looking for, but libremd is an Invidious-style front end for the IMDb. It manages to scrape quite a bit from them, though not everything.