There is no 3:2 resolution on normal chromebooks, just normal resolutions. It's more due to the video BIOS missing / being strange when using the SeaBIOS payload beneath chromebook's Coreboot from what I can understand, and gfxboot not coping with it.
I believe 16.04 would work just as well if unetbootin would work for 16.04 images, ie removing gfxboot completely and replacing it with other first menu showing code.
There is no 3:2 resolution on normal chromebooks, just normal resolutions. It's more due to the video BIOS missing / being strange when using the SeaBIOS payload beneath chromebook's Coreboot from what I can understand, and gfxboot not coping with it.
I believe 16.04 would work just as well if unetbootin would work for 16.04 images, ie removing gfxboot completely and replacing it with other first menu showing code.