It seems my eMails to gnupg-devel@gnupg.org do reach the list …

I understand the desire for stable behavior, and i agree that a change here might affect verification of existing signatures (and might mean producing signatures that will be misinterpreted by older versions).

This has been implemented and tested to be compatible with PGP - a looong time ago. iirc this was discussed around 1999 but might be only by private mail between the PGP hackers and me. Thus any change now might break PGP - which is still widely used (although mostly for encryption).

Oh yeah the idea to implement aliases is more than 20 years old. I guess it is even older. Thanks.

I disabled this for offline keys because I erroneously assumed that one would need the primary key for changing the password. We can simply replace the check for the primary secret key with a check for any secret subkey that's stored on disk.