  We address the near-collinear expansion of multiparticle NMHV amplitudes,
namely, the heptagon and octagons in the dual language of null polygonal super
Wilson loops. In particular, we verify multiparticle factorization of charged
pentagon transitions in terms of pentagons for single flux-tube excitations
within the framework of refined operator product expansion. We find a perfect
agreement with available tree and one-loop data.
