Probably a bad idea. If you really wanted to do it, you should add plug-in support to your main project, then create a separate repo, maybe under a different account, with the potentially illegal yts download plug-in. That way only the plug-in repo would get DMCAed and could be mirrored by other people, or hosted off GitHub.

The reason they were banned on leetx is because they sold out their user email lists to an anti-piracy law firm which tried to extort money from people. I wouldn’t trust people like that. I especially would be wary of subjecting users to people like that. Torrent freak has coverage if you care to search.

I think the way lots of projects handle something like that is to add a plugin system to the main project, and then offer it as a plugin in a different repo.

GitHub definitely would and has in the past. YouTube-dl is on GitHub and gets a pass because it is used by researchers and archivists, both are fair use. forgejo.org would let you be your own fedi-github and might be worth checking out (could be easier than designing a plugin system and additional repos).

make this functionality into a plugin that you publish under a different account, that way you can have this functionality while maintaining plausible deniability