So I now have all the wing surfaces installed and hooked up to servos. I'm pretty happy with the outcome. Let me tell you: this airframe is ROBUST. And it's fairly light for its incredible strength.
And here's how I set up the controls: instead of using a channel for each servo in the wings (six channels!) I decided to use a Y-connector for the two flaps in each wing for a total of 4 channels. The only downside is it takes careful matching of the servo horn and linkage installations and there will always be TINY differences in each flap that can't be tuned out - but certainly not enough to notice in flight. Here's a quick short of the outcome:
I love how, at full flap, the control horn is all the way down pointing at the flap which means that even though the air loads increase the total torque on the servo is reduced and at full flap there is ZERO torque on the servo. It's like magic!
EDIT: This is going to get lost in the all the previous words HOWEVER: I meant to mention that in my installation the G10 glass flap control levers were maybe 1/32 or a millimeter too long which will cause them to scrape on the surface of the top wing surface when arcing fore and aft. Fortunately there is plenty of material on the horn there to remove so we still have adequate material for the linkage hole.