I don’t think the speaker processor would do it for you.

The way I would approach this problem is to set up the desk without a main buss. Then create 7 mono auxes. I’d assign each mono aux as an out to a speaker (Left 1, Left 2, Right 1, Right 2, Center 1, Center 2, Sub). Then I’d just run the entire system like I would normally run an aux fed sub. Set all of those auxes as POST fader. To setup the show I’d press MIX on the IP strip and bring up the aux for each speaker that needs that channel and I’d vary the levels to control the stereo positioning. Then I’d assign all 7 auxes to a DCA and use that DCA to control the main output level.

I had a BE once time request a aux fed center and an aux fed sub. This just takes that idea farther. You’d lose the ability to change the panning with the rotary encoder but this is the easiest way I see to setup what you want.

-d