NAT Traversal with libp2p

Hey folks,

I am currently working on a simple chat application for a prove of concept of different NAT traversal approaches. Under concepts there is a kind of waterfall approach described, to test different NAT traversal techniques. But it seams like thats all not really implemented jet and circuit relay is mainly used.

Am I right here or am I missing out on something ?

Best regards and thanks for any help !