I WOULD RECOMMEND THAT YOU MOUNT THE UPPER WING AT -1/2 TO -1 DEG NEG
MOST ALL BIPES I HAVE BUILT HAVE HAD THIS ARRANGEMENT AND FLY GREAT.
THIS ALLOWS THE BOTTOM WING TO STALL BEFORE THE UPPER. MY DIRECT CONNECTION ULTIMATE IS SET UP THIS WAY AND IT WORKS.
JMO. HOPE THIS HELPS.