One other handy feature that we're using is the ability for Vault to set user IDs in the signed key ID field which then get logged by sshd on the remote host.

One other handy feature that we're using is the ability for Vault to set user IDs in the signed key ID field which then get logged by sshd on the remote host. That way we can still audit who exactly logged in if using a single user on the remote host.