I think this is the best strategy. Put your money in your mortgage, and once your EFC doesn’t matter, do a cash out to recapture it if you wish. Most schools do not count home equity as an asset.
Or, you could do what a friend recently did. Get divorced, end up laid off, and spend your available cash on living expenses. He looked dirt poor and his daughter got a free ride to the University of Minnesota. Once EFC didn’t matter, he spun up his old consulting side gig and is doing quite well.