While we were focusing exclusively on reef-uni, we landed a lot of ebuild structure improvements and refactoring to decrease human error and reduce duplication in build dependencies. For example: https://bugs.chromium.org/p/chromium/issues/detail?id=747477 . While that bug targeted "baseboard" and we don't have that in coral, there's a few things that we should bring over there.

Other examples:
camera: https://b.corp.google.com/issues/63387838
audio: https://b.corp.google.com/issues/64156591, https://b.corp.google.com/issues/63350999 & https://b.corp.google.com/issues/63386669
touch firmware: https://b.corp.google.com/issues/64724874 & https://b.corp.google.com/issues/63387905
ARC++ hardware features: https://b.corp.google.com/issues/63386917
powerd: https://b.corp.google.com/issues/63094714
bluetooth: https://b.corp.google.com/issues/63111731
activate-date: https://b.corp.google.com/issues/63387767