Two Squeezelite instances with front and rear speaker output on one audio device

Hello,

I have bought an Odroid XU4 to be used as a NAS solution (USB3) and to drive two instances of Squeezelite to run two different rooms.
Unfortunately the XU4 has no 3.5mm audio output, therefore I bought an HDMI-to-audio adapter. Again, unfortunately, I cannot get this HDMI adapter to work.

So to get two rooms I would have to use two USB audio sticks, but I need the USB3 connectors for the disks.

I found some USB audio 5.1 adapters on the web that have 2 audio-out jacks (front and rear speakers) in one device, but I haven't bought yet.

Does somebody know if it is possible to assign each Squeezelite instance to one pair of these connectors?
So one Squeezelite instance=room drives the front speaker jack, and one instance drives the rear speaker jack?

If someone has such an USB (or PCI) audio adapter with multiple outputs, could someone try this?

Thank you for your help!
Christian