I now build the sunfish unoffiicial builds, and post them here: Unofficial builds for Google Pixel devices
But I was recently made aware there are official sunfish builds as well, I am interested if anyone would be willing to test migrating from unofficial to official as I don’t have a device that has both builds available to test.
But back to your question, I think you will have to look at the Lineage builds to see if they contain the update, I couldn’t honestly say offhand. I do see some reddit threads indicating that users wanting to avoid the “battery update” happily moved to Lineage instead. I guess my question is if the update was just at the software level (if so then I assume not included in Lineage) or if instead it was a firmware update (basically “below” the OS) in which case it may be permanent??