Correct. What might be interesting to add to this: you can't query Certificate Transparency servers by certificate. You can query them by index or by using an S

Correct. What might be interesting to add to this: you can't query Certificate Transparency servers by certificate. You can query them by index or by using an SCT hash, but if you want a definitive answer to "when was this certificate first logged?" you'll need to process the log completely. CT is not designed for live-checking of certificates, only for monitoring by domain owners.