You don't need to do anything different from the instructions of whatever community-build you want to use after updating, the update only unlocks the oem partition, it doesn't force you to use it. The flash.sh is specific for the build you want to use and changing it to write the blobs to the oem-partition would only break the community-build because it still expects them to be in the old position.

The only place where you'll have to replace a script is the official release because that one will (most likely) only ship with the windows-script.