I was suggesting it more for the bra to prevent it from looping back around on itself (clarification men it is important!) also I just love how finagally computer math is with super massive numbers and Im really impressed that you solved it the way you did!
Couple more peanut gallery comments when the fox does reach "max size" you could always cheat! Shrink the fox model and slowly decrease the frame to give the 'illusion' of getting more 'uge without the boobs incrementing past a certain number.
And last I'm not sure if this would be easy or impossible with how your math is set up but having 'scaling rings' that sorta appear around the edge then shrink around the fox would give some sort of visual reference to how big she is without relying solely on the single number (size of a house, size of the moon, the sun, the observable galaxy etc)
Also thanks for the time your putting into this! You are amazing!