Horozontal stabs DO produce lift
Here is the gist of what we learn fron the folding stab experiment
The CG does NOT have to be ahead of
the aero center of the WING (which would indeed require a
down-pushing tail)
Instead, the cg must be ahead of the aero center of THE WING AND TAIL
SUMMED TOGETHER.
Once you add any amount of hstab area behind the main wing, you will be able to move the C.G. rearward of the main wing's AC without loosing stability. The more area added to the hstab the more you can move the C.G. back. When the area of the hstab equals the area of the main wing you have a tandem wing. Add even more area and you have the main wing smaller than the hstab which is a canard.