It would be really interesting to learn more about the technical details of the "UDP-based protocol" Warp uses

It's WireGuard [1] coupled with tech from our Mobile SDK [2] and (in the case of Warp+) Argo [3]

1- https://github.com/cloudflare/boringtun

2- https://blog.cloudflare.com/mobile-sdk-acceleration/

3- https://www.cloudflare.com/products/argo-smart-routing/