I in community post i found it in multiple posts that lets encrypt CA submit precert to Log server and receive SCT which it embeds into the final cert and again submit it to Log server
Lets understand it by a live example : -
Precert : - https://crt.sh/?id=2661737250
|2020-04-03 08:03:25 UTC | 275084726 | Cloudflare | https://ct.cloudflare.com/logs/nimbus2020|
|2020-04-03 08:03:25 UTC | 460285901 | Google | https://ct.googleapis.com/logs/xenon2020|
Final cert :- https://crt.sh/?id=2661738285
|2020-04-03 08:03:25 UTC | 475197205 | Google | https://ct.googleapis.com/logs/argon2020|
|2020-04-03 08:03:25 UTC | 460286022 | Google | https://ct.googleapis.com/logs/xenon2020|
|2020-04-06 00:03:45 UTC | 1091178038 | Google | https://ct.googleapis.com/rocketeer|
|2020-04-06 02:08:33 UTC | 1027005246 | Google | https://ct.googleapis.com/pilot|
precert is submitted to one google ( xenon ) and one non google ( cloudflare ) CT Log Server and the replied SCT is embeded in final cert as certi extension
Now as far as i read about the CT logging in certificates having embedded SCT domain server ( the certificate owner ) has no rule in submitting the final certifcate to the CT log server so this means Lets Encrypt CA is submitting final leaf certificate to 4 different Log servers to 4 Different google Log servers that too with 3 days delay ??