Mine is CG-NAT + dynamic IP. I haven't tried, but there are settings to forward port, so I guess incoming is allowed.
So no IPv6?
I can possibly run Wireguard endpoint on Pi. But would I need DDNS to work around the dynamic IP?
That depends heavily on how often your IP changes. Some of my residential dynamic IPs barely change once a year. Things that are behind CG-NAT, though, can change every hour.
My current attempt involved making a VPS with static IP The end point. With some UDP hole punching, I was hoping to reduce the latency between the peers, with some way to reduce P2P latency such as UDP Hole punching. (VPS to either peer has high latency, peer to peer has low latency.)
That's tough. Peer to peer is really tough behind CG-NAT. I'd love to hear what works for you.
John