We never ended up using this and it makes it much harder to reason about the listeners.
An explanation: for the moment I separated out all of the listeners in the struct, even though one should suffice, because when I did it that way first I was hitting some really weird and hard to find intermittent behavior where it seemed like the listeners were getting crossed. So I re-did it this way with each listener very explicitly referenced. I'm happy to make a follow-up PR that attempts to combine them all into a single listener without hitting the issues I did, if desired, but at least doing it via a separate PR means that it won't be something with removing the ALPN muxer that is at fault.
Jeff Mitchell
07dc3db974