Have you heard the good news of Merkle Tree Certificates[1,2]? They include the transparency cryptography directly in the certificate issuance pipeline. This has multiple benefits, one of them being way smaller transparency logs.
1: https://www.youtube.com/watch?v=uSP9uT_wBDw A great explainer of how they work and why they're better.
2: https://davidben.github.io/merkle-tree-certs/draft-davidben-... The current working draft
Yep ... Saves about 40%, seen one of the implementations. One of the guys posting here from time to time has a working version.