The biggest reasoning on that was the assumption that ball-less futa lovers would prefer not to have semen. That may end up being another option to toggle to provide further customization. That's one of those "not really my fetish so just kind of guessing what people want" situations.
Viewing post in Aric's Expansion Rebred
I responded without actually checking my script. I had already applied a check to apply a base cum production of 1 to Futa without balls, but it was never triggering because of an Or instead of And check in the previous check which was only applying based on the ball size (which was obviously 0).
Fixed in 07.1