I am aware of Yggdrassil and I tried it myself, works well.

I don't have any specific plans to use it, but I think Pkarr can help Yggdrassil, and I would be happy to help the Yggdrassil team or anyone who wants to hack them together. 

We already can use upnp or hole punching to run servers from anywhere, but Pkarr is not suited for records that change often (caching and TTL is important for scaling) so anything that allows servers to have stable endpoints is welcome. 

 Yes, exactly. They can work as complements.