I think that DLNA will only server the current library.
You might find another way to do this though. Why do you want to keep them separate?
Are you playing from the "clients" or playing to them?
Why do people separate anything? To make a distinction. My 16/44 library is very clean and organized. My high Rez library is the Wild Wild west. I do not want the two commingled. At all.
I am playing from the clients, as it should be. My machine running JRiver is virtualized, on a noisy Dell enterprise server, in my basement, behind closed doors. It is rarely touched. I use the app via RDP to organize and import files into the library now and then. The player devices are Olive ONE, an Auralic Aries, sometimes JRemote on an iPad, and a Sonos which scans the SMB share and it only cares about tags. Again, separation is vital. JRiver is a versatile management interface and an (OK) back end to serve up this stuff, but could still use a lot improvement if you consider that more and more of your customers do not actually sit in front of their computers to use it.
Additionally, I have different devices which have (or don't have) limitations. I want to know exactly what type of media I am streaming and I do not want any transcoding. Either it plays full fidelity or not at all. I don't even want to see it if it is not playing at native resolution. You guys claim to understand the audiophile community. On the JRiver homepage, the saying under the Audio section is "If perfect audio is your goal..." Well, transcoding is not perfect. Transcoding is gross and a bastardization of the original. I won't have it.
If multiple library DLNA hosting from one instance is not possible (doesn't sound like it is without running another VM with another instance of JRiver), 6233638 mentions the ability to create views based on Sample Rate. I have "hi-Rez" albums that are 24/44.1, so just filtering based on Sample Rate alone is insufficient. Can I have multiple filters on these library views?
Oh, and if I
should be keeping only one library, and that is the way it
should be done, then you need to talk to your UX folks and remove the option for multiple library management. The existence of the feature implies I
should be able to do more with it than is possible.
Additionally, can we make what I'm asking for here a feature request, please? I was very much hoping MC20 would include a more mature feature set. I still am not realizing any difference between 19 and 20 other than a lighter wallet...
Or hell, make something better for only audio management and audio servers. With a better user interface or a client/server architecture. Call it "Platinum," charge us $99 for it and make it exclusive. You'll have people busting down your doors to get it. I am serious.