Bowhuntr64,
Interesting and informative as always.... You mentioned that you tested 125 grain heads comparatively. However, unless I missed it, I didn't hear you mention the total arrow weight and the front of center (FOC) weight distribution on the test arrows.
According to the most recent data, inclusive of Ashby's latest testing, the true benefits of the single-bevel design do not really reveal themselves until the total arrow weight is north of 600 grains and the FOC is in the 19-30% range. That heavier arrow, in combination with a significant FOC build, are supposed to be the two most prominent factors that create the most desirable single-bevel design performance characteristics of splitting bone, spiral cutting, and overall penetration. Even Ashby noted that the benefits of the single-bevel design were significantly less prominent with lighter arrows and less FOC.
Additionally, the single-bevel design forces immediate arrow rotation just as if you had right (or left) helical front fletches that, in theory, result in better downrange accuracy especially with higher FOC builds...
I would be very interested to see what your side-by-side penetration results would be with arrows of at least 600 grains, and 25% or more of FOC. I would also be very interested to see the comparison in the groups you can shoot out to 30-40-50 yards and beyond... Maybe something to consider for single-bevel vs. double-bevel Part-2...?
Some very interesting recent data on this subject for those who have not yet seen it in the link below:
https://dangercloseoutdoors.com/12-factors