Flow/Blend: Same stepover/cusp values specified on similar geometry but much different results?

[eerier_bleach0f]

Settings:

Changing the blend's stepover calc to "on surface" yields much closer results but there's still 2 more passes than the blend.

[programming2C78B]

Posted this before too, also with Scallop. I ended up just looking at the toolpath data and finding what the "real" stepover was! I find for scallop I basically double what I want to use (is it considering the gap that it does on an entire loop instead of per stepover?) and no one at Autodesk could explain the math behind it. Sad.