Following up to the issue: #12037
RPC call dumpprivkey [P2SH over P2WPKH] does not work. Is there a reason why this not implemented or just nobody worked on it?
This is currently being implemented as part of #11403. See commit https://github.com/bitcoin/bitcoin/pull/11403/commits/4ef27d945e99310e018b0e2a30c85e9620738c5a.