[ssh_x509] Question RE: store identities(keys) in PKCS#8 PEM format

[ssh_x509 at roumenpetrov.info]

Roumen,
As I'm upgrading to the latest release of PKIX-SSH, I'm seeing some changes in ssh-keygen. It appears that in release 12.3 (and commit 5e0974257d55618d71063634ade9dde18b540d23), ssh-keygen changed to support PKCS#8 keys and no longer support writing PKCS#1 key format. Is that accurate? My apologies if I am completely misunderstanding the change here, but if so, why the decision to leave PKCS#1 behind? 

Thanks,
Alex