Yeah, but I mean you just have to have something on the transport layer, you can't just encapsulate application layer into network skipping network, that's not how the network stack works.
Perhaps it's because I'm tired but I can't make sense of your objection.
As I said you could implement it by having TCP/UDP as is, just with a fixed port number. This wouldn't be unlike the myriad of other conventions that litter IPv6, such as using /64 for a host or ULA's having a certain prefix.
Got it, makes sense. It just seems more like an architectural decision to me than something related to the network stack - that's why I got confused. You can come up with your own convention and use it within a local network. One of the downsides of this approach - it will clutter up the routing table, but that’s probably not a big deal.
I usually prefer to use some kind of demultiplexer, like a reverse proxy, to handle the conversions.
As I said you could implement it by having TCP/UDP as is, just with a fixed port number. This wouldn't be unlike the myriad of other conventions that litter IPv6, such as using /64 for a host or ULA's having a certain prefix.