Unix Domain Sockets are the standard mechanism for app->sidecar communication at Google (ex: Talking to the TI envelope for logging etc.)
No idea what "TI Envelope" is, and a Google search doesn't come up with usable results (oh the irony...) - if it's a logging/metric thing, those are hard to get to perform well regardless of socket type. We ended up using batching with mmap'd buffers for crash analysis. (I.e. the mmap part only comes in if the process terminates abnormally, so we can recover batched unwritten bits.)
No, I am just saying that the unix socket is not Brawndo (or maybe it is?), it does not necessarily have what IPCs crave. Sprinkling it into your architecture may or may not be relevant to the efficiency and performance of the result.
We started out discussing AF_UNIX vs. AF_INET6. If you can conceptually use something faster than sockets that's great, but if you're down to a socket, unix domain will generally beat inet domain...