Well… I assume that might be illegal. Or maybe these rules would only apply to public software? For sure it wouldn’t be enforceable, and it would still allow criminals to use it to communicate privately between each other, but it would make it harder to exploit mainstream public apps (e.g.: WhatsApp) to scam or exploit weaker individuals.

I am not OP, but that would be the ideal solution for me. Unfortunately, KPXC does not support communication with the GPG agent and the team is not interested in adding this feature due to it being «[…] far more complicated than ssh-key management. There are already excellent tools for this, Kleopatra being the best».