So RebaLynn1960 suggested that we lower the threshold to something like -20. I looked at the data and code for bottle-feeding, and found that this was easy to do. In fact, considering how easy it actually is, I'm surprised something like this didn't already exist! So here it is!
This mod does NOT affect breast-feeding, but it *will* play nice with my BO - Feed Baby mod, lowering the number of times bottle-feeding of a baby will occur in case breast-feeding isn't available for that baby.
Since this mod affects a system that has been around since Basegame, it should be fine for all games. And if any other mod conflicts with this (I don't see how, since nobody else seems to have done something similar before), then load my mod last, and everything will be fine.
Credits: Thanks go to RebaLynn1960 for suggesting this to me.