You might ask.
I’m looking at a way of having a redundant laptop and being able to switch to it quickly, even mid-song.
A quick and easy way would be to have one usb audio interface and 2 laptops.
Both laptops receive MIDI from the controllers.
They play simultaneously.
If the main laptop crashes you pull the usb cable from one laptop and insert into the backup.
Cantabile would need a modified ‘null audio’ device though. One that plays null but is also sensing to detect if the main audio interface is connected. Once connected it switches to that.
The usb interface runs on external power.
The interface is connected to a switch (eg Aten) so the swap is just a button press and not a cable switch.