  We reformulate differential equations (DEs) for Feynman integrals to avoid
doubled propagators in intermediate steps. External momentum derivatives are
dressed with loop momentum derivatives to form tangent vectors to unitarity cut
surfaces, in a way inspired by unitarity-compatible IBP reduction. For the
one-loop box, our method directly produces the final DEs without any
integration-by-parts reduction. We further illustrate the method by deriving
maximal-cut level differential equations for two-loop nonplanar five-point
integrals, whose exact expressions are yet unknown. We speed up the computation
using finite field techniques and rational function reconstruction.
