Ben McGinnes via luv-main writes:
[...] I still keep 1.4 around for [...] or making 16K keys (they're a waste of time and effort, if you must be that paranoid then 8K is still fine and 4K for comms ... well, it was good enough for Ed Snowden). [...] Large key support from 2.1 will basically stop at 8K, if you really want to make a 16K key then the easiest way is to modify the source for 1.4. You'll need to raise the key size maximums and increase the secmem. I'll leave the rest as an exercise to those who should know better, but otherwise think they know what they're doing.
When someone says "I need 16K RSA keys", don't they really mean "I want EC keys"? Because, like, RSA needs to be a lot longer than EC to provide the same security level. Obviously there's problems with that in practice (for GPG) because you need to interact with people still running gpg1 --- cf. EC in OpenSSH.