It seems that most chrome devices (chromebooks, chromeboxes, etc.) support the same alt modes (DP alt mode and Google Firmware Update). Additionally, the custom VDMs seem to be the same across most boards as well.

Maybe we could create a "common" USB PD Policy that has the standard "chrome" alt modes and VDMs, but also allow boards to override them (or not include them for PD peripherals). This would help in deduplicating the code and avoiding copypasta.