[chabsf]

Furthermore, in the case where I'm using protobufs as a necessary evil of grpc, what's the best alternative here?

[romed]

protos are not necessary for grpc. You can use whatever payload format you want to use.

[tathougies]

JSON/custom binary format + HTTP2?

[chabsf]

HTTP2 is just the transport, there would be a ton of machinery to implement in each language in the stack.