A factorization hypothesis is tested by examining a form factor of the ωπ production in hadronic B0→ D∗±ωπ∓ decays. The form factor is compared to that from available τ -lepton as well as e+e− data using the conserved vector current hypothesis. The difference of normalizations of form factor shapes from B and τ (e+e−) data indicates the important role of the large Nc limit in QCD. Moreover, the growth of the difference between the form factors with the ωπ invariant mass is related to the perturbative QCD corrections of factorization. The current precision of B data does not allow one to find any evidence of corrections to factorization. A promising study could be performed with the Belle II and LHCb data sets.