Glad to hear you got a solution.
Unfortunately, that solution isn't at all what I was suggesting, and there seem to be some issues with the theory and math in there but I just don't have the time to troubleshoot it all or deliver a smoothed-out one. This is definitely beyond the scope of the kind of GSAP-specific help we offer in these forums. If you still need some help on a consulting basis, feel free to PM me. Or maybe someone else has time to dig in and craft a solution for ya. Congrats on getting this far, though! I know it's a tricky challenge