I clearly missed the firmware announcement re ID40, which I've now found. This seems like a good option. For my complete understanding:

1. I assume I'd still have to hook up an amplifier again to my 861 to use with the non-DSP speakers outside my main zone?
2. How would inputs know which speakers to output to?
3. Could someone listen to another input (e.g. TV, which is all via the 861 as I don't have any speakers on my TV) if I'm listening to Sooloos in another zone?

Also to confirm, ID40:
4. Adds a 2nd Sooloos zone to my system
5. Improves audio quality to both zones

Thank you to everyone for your help.

Trinnov Altitude 32-8-16, Meridian 271, Front: DSP7200SE, Centre: DSP7200SEHC, Rear: DSP3200, Ceiling Front & Rear: DSP320.2, Sub: Velodyne DD15+, MC200, Oppo 203, Sony VPL-VW360es, Lumagen 5348.