This is very cool. Could have needed than in my last project where in our load-testing with j-meter everything was fine and in production our nodes would fly out of the cluster like flies. I haven't looked deeply at it but I think session support would be very important, so that you don't just forward the requests but take care to maybe rewrite the session cookie to the server assigned one and when rate-limiting make sure to prefer to keep existing user sessions. From my expirience the problems we had on production were often because of some weird steps user took, which you might not catch if you don't make sure to exactly keep the users sessions in sync.