Is this about the gui not offering e.g. the wrong algorithm or key sizes in the first place? If so, then we have to either hard-code it in kleopatra, or communicate it from gnupg. I guess at this point, we'll have to hard-code it :/

Fwiw, gnupg kind of refuses to create non-conforming keys, but this is rather by accident. It creates the key, and then fails to create the self-signature because the key is not compliant. Only interactive keygeneration actually take the compliance mode into consideration.

I patched Kleopatra only to offer compliant options in the generation dialog. Patch is pending.