im just saying that it is possible for a binding to damage a boot.
also. theres an industry standard for the part of a boot that fits in the bindings. the width, the shape of the toe, the heel, etc.
however the industry standard for a kids boot differs from an adult boot. i would be concerned about using an adult boot in a junior binding for the same issue of wearing away at the boot due to improper contact on top of the toe and heel.
im not the best source of info, but i hope what i had to say inspires you to more seriously seek out the information you need
"I look at it like this; the park is like a canvas, you practice the art, but being out on a real mountain is like experiencing the painting. I want to get out there. Explore." -Parker White