You could try leaning it over on a slant, like 60 degrees so it’s not in aggressive overhang territory, and then design in a custom support that can be cut off after. Since it doesn’t need to be optically anything the marks from the support cutaway don’t matter.

Afaik you need some external resource to coordinate the punch. The STUN protocol is purpose built for this, and both clients need to be able to reach a STUN server to coordinate which port and public IP they’ll try to connect to each other on. I assume this does something similar but with p2p network tech instead of a STUN server.