Depending on the gnupg version set as dependency (and considered standard) for gentoo the algorithm IDs of the signing and primary keys should be restricted. The current whitelist should be [1,3,17] for RSA and DSA keys, excluding e.g. EdDSA and ECDSA algorithms (the latter in RFC6637, the former is implemented in gnupg 2.1 but no I-D exists yet)
gkeys was disbanded a while ago.