Apart from automation being an end in itself, I wanted to be able to easily put new SeaBIOS payloads into the firmware mods, and ensure consistency. All the firmware mods now contain the same version of SeaBIOS (from the master branch), the major additional feature (for some models at least) being SD card support.
I expect to make further payload updates as and when salient features become available in SeaBIOS master. When an update is made there will be a small period (probably less than an hour) where the script goes into maintenance mode, and I test the payload on one of each of the last 4 generations of Chromebook (Sandy/Ivybridge, Haswell, Baytrail and Broadwell). Please use the community to direct all feedback.