First, this is almost exactly what I've been looking for... the video compression you guys use to transmit from a secondary to a primary is fan-freakin-tastic - even at 4k resolutions, there's very little stutter.
There's just one thing I can't figure out - how can I show show monitor 1 of the secondary on monitor 1 of the primary, and monitor 2 of the secondary on monitor 2 of the primary at the same time. They're both set up to use the same monitors independently, but I can't get this to work under Multiplicity. I can get monitor 1 or 2 of the secondary to show on either 1 or 2 of the primary, but not in a dual monitor setup like one would expect. Is this just not a supported feature?