I must have looked that up five times by now, but did segwit actually forbid high-s ECDSA signatures in witnesses, esp. in standard single-sig constructions such as P2SH-P2WPKH or P2WPKH? Or are high-s signatures still only non-standard even in segwit inputs?
(I'm aware that the transaction malleability problem due to low-s/high-s is mitigated by moving the signature into the witness, that's not my question.)