@B.Will Copy that. That's what I feared I'd have to do, but already putting together the order for some 12/2 romex to get it done. Thanks for the input!

@B.Will But where do I get Neutral/Common for Box 2's Kasa switch?

First, I want to start by saying I want to use TWO HS210s in this 3-way set up. If i have to run more romex, I will. I'd prefer not to. The Kasa app forces me to use a dumb switch with ONE HS210...