Scrutinizing B¯→D∗Dπℓ−ν¯ℓ$$ \overline{B}\to {D}^{\ast}\left(D\pi \right){\ell}^{-}{\overline{\nu}}_{\ell } $$ and B¯→D∗Dγℓ−ν¯ℓ$$ \overline{B}\to {D}^{\ast}\left(D\upgamma \right){\ell}^{-}{\overline{\nu}}_{\ell } $$ in search of new physics footprints