I am definitely using Weave Net for my trivial single-node cluster because it was the only CNI option that included a one-liner to install.
I have never had any reason to try a different one, the pods can talk to each other, "does what it says on the tin"... and on top of that but unrelated, their webinars tend to be star-studded and very informative.
Very cool. Eventually I'd like to turn Colossus into something more like what you have here, i.e. a "real" backend that does something meaningful. The good news is that the Bazel + gRPC plumbing was the hard part. Adding new, meaningful services will be pretty trivial going forward.