Hi Fred. You are right about the decalage. I had to raise the tailplane LE by a few mils to set the decalage at about 1' and not the 5' previously. I can check where my CofG is, but about 50mm is supposed to be right. I think the manual says 60mm +/- 10mm either way.
You likely remember the roller coaster ride when we towed it before changing the tailplane incidence. I need to fly it off the slope yet to check out the adjustment, but it is widely reported on the internet to make this change.