An introduction to computer audio
Perhaps not a very spectacular picture but JRMC supports zones.
If your PC have multiple outputs you can use this for multi room audio.
I use it the other way round.
My PC has 2 outputs and my DAC the same inputs; USB and SPDIF.
Let zone 1 use the USB and zone 2 the SPDIF.
This allows for a rapid A/B between the two.
Use the link option to synchronize the two zones.
You can define rules to switch automatically between zones.