"any of the public keys in your certificate chain" includes your own certificate, so yes, that's possible. However, if your main and backup key is lost or comp

"any of the public keys in your certificate chain" includes your own certificate, so yes, that's possible. However, if your main and backup key is lost or compromised, you have essentially bricked your domain. That's why most real-life deployments pin to two CAs instead (since CAs are generally better at managing keys).