One of the main goals of Flavor Physics is to overconstrain the CKM matrix. Non-perturbative QCD, however, makes this challenging by introducing hadronic matrix elements that cannot be reliably calculated. In our work, we use the approximate U-spin symmetry (d and s quark exchange) to get around this problem. In my talk, I will argue that, despite the relatively large breaking of the order 30%, the systematic expansion in U-spin breaking can be used for precision physics. I will also motivate the study of multibody hadron decays as a prospective direction where high precision theoretical predictions can be achieved. The first steps towards precision physics with U-spin are realized using our novel approach to deriving U-spin amplitude sum rules, which will be the main focus of this talk.