The IETF has specs for IP-over-HTTP/3 (MASQUE CONNECT-IP, RFC 9484) and Multipath QUIC, but no open-source implementation combines both. I implemented MASQUE CONNECT-IP on XQUIC (which already had Multipath QUIC), and wrote a new multipath scheduler designed for QUIC Datagrams, then built a VPN layer on that.

This scheduler (WLB) distributes TCP flows across paths proportional to capacity — with asymmetric paths, it reaches 319 Mbps (84% of theoretical max), +21% over the default MinRTT scheduler at 16 parallel flows. Failover is zero downtime.

Benchmarks and graphs in docs/benchmarks_netns.md.