I want to no longer use an OpenPGP SmartCard but keep the original secret key, e.g. to read old messages, to use it on a mobile device or in Thunderbird 78.2.1 without GnuPG. I do have my pubkey and the sk_KEYID.gpg – which was saved during "on-card" key generation. Werner Koch proposed to implement a way to create a private-keys-v1.d/xxx.key file from a sk_KEYID.gpg file and asked to open this feature request.