Reading up on the discussion here - hole punching seems like an interesting idea to increase network connectivity and robustness to network adversaries.
A campus network that I used for testing had APDM and varying external IP addresses. IPv6 was disabled.
This recent paper claims a ~70% success rate with both TCP and QUIC (UDP-based transport) using libp2p’s DCUtR.
Thinking ahead if UDP hole punching proves to be much more effective, has there been any discussion in implementing QUIC or a custom UDP-based transport in core?