I went back to the patterning board today at 15 yards from muzzle to board. Instead of stacking felt dots as a rib I used pre-cut and measured wooden blocks as better shims. The sight picture was to keep the sight on the flat (or shim) and the dove on the sight like it was sitting on it.
Load was 1oz scoop Scheutzen 2F, 3 thin cards, 1/8oz #7.5 and another thin card. Bag was under the first ramrod pipe for support, butt squared tight to shoulder.
Since I can't find pictures of anyone else's pattern results I want to share mine in case anyone finds themselves with the same issue.
Shot #1 was taken with no shim. It shows the overall pattern to be good but the center is low (8-9") and a bit to the right.

Shot #2 was taken at the same paper to compare the overlay. I considered both identical.

Shot #3 was with new paper and a 3/8" shim. This proved about 5-6" higher than I'd like. Shot #4 (not shown) duplicated the result.

Shot #5 was with a 5/16" shim and shows the pattern right where I want it. Shot #6 (not shown) duplicated the result.

I think the 5/16 height will allow me to have the same sight picture that I'm used to. In looking up other fowler barrel profiles, many seem to have a wider breech and shorter barrel so that the sight slope is steeper than this one and those may shoot closer to what many like myself (new to flintlock and 44" barrels) think they should. I also think the raised tang that is seen on so many originals may have solved for this as well. Or at least reduced it.
I'd like to add that I kept the same powder and cards while reducing shot to 1oz and 7/8oz and while pellet count was slightly reduced, patterns remained centered at 15 yards and well spaced.