For another approach that has actually been deployed at scale by OpenAI there's MRC:

Blog post: https://openai.com/index/mrc-supercomputer-networking/

Paper: https://cdn.openai.com/pdf/resilient-ai-supercomputer-networ...

Spec: https://www.opencompute.org/documents/ocp-mrc-1-0-pdf

MRC is an extension of RoCE that does out-of-order packet delivery, packet spraying across all available paths using SRv6 routing, combination of ECN and packet trimming for congestion control (so sender-based CC like TCP and unlike Homa).