NJoy
Here I grow again!
Just wanted to add that I think back lengths help to keep things consistent. If we use below bellybutton, then you'd have to bring your hair forward or tie a belt around you at belly button level so you can guage where on your back bellybutton position is.
Otherwise if you pull your hair forward to see if it reaches you bellybutton, you'd have the issue of "losing some length" coz your hair has to travel forward first before down:
I suppose you can turn your head to one side so you bring the hair forward and pull it down to your belly button:
But I just like the idea of all length checks being on the same side: the back.
Dang Nonie. You be ON it! Customized visuals and all. Go girl!