The thing is that anyone coming from JRiver immediately sees JRiver ASIO as an (un-enabled) endpoint. So that part of the functionality exists. But from what you are saying that was probably from years ago. All I did was enable it.
I already started in baby steps trying to get system out working before UPnP. I couldn’t rule out I was doing something wrong so I ended up raising a support ticket. The details are here:
From what you are saying, the answer to my question is that, no, JRiver ASIO is not supported, mainly because no one was asking for it. But I imagine a lot of these things are moving targets. So maybe a better question I should have asked is,
“If there has been a lot of sunk effort, half getting JRiver ASIO working, is there a DNLA business case to complete the task?”