Você já tentou essa opção na página de manual de gpg
? Eu achei pesquisando aquela página por "inseguro" (soava familiar, provavelmente da navegação)
--no-permission-warning
Suppress the warning about unsafe file and home directory
(--homedir) permissions. Note that the permission checks that
GnuPG performs are not intended to be authoritative, but rather
they simply warn about certain common permission problems. Do
not assume that the lack of a warning means that your system is
secure.
Note that the warning for unsafe --homedir permissions cannot be
suppressed in the gpg.conf file, as this would allow an attacker
to place an unsafe gpg.conf file in place, and use this file to
suppress warnings about itself. The --homedir permissions warn‐
ing may only be suppressed on the command line.
Ou talvez fazer uma cópia da pasta raiz de alguns arquivos gpg, apenas para verificar assinaturas?