Sane played wingback a few times. Chelsea, Southampton and few other games. He was phenomenal. Those around him weren't. But he can definitely fill that roll if needed to tactically.
He wasn't a wingback. He was a winger.
We played 3241 and he was a winger. Just like Robben & Ribery were wingers not wing backs when Pep played the same formation at Bayern.
We could definitely play him in that role again, he was great, but he wasn't a wingback and 99% of his defensive contribution was staying high, pinning back Moses who was too scared to go forwards and leave Sané with space.