Nico Huber has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/31324 )
Change subject: src/device/Kconfig: Add Kconfig options to choose a default VESA mode ......................................................................
Patch Set 4:
Why add 100 lines to fix one board if we can fix all boards without adding any?
Sorry for this, I was not sure that all the coreboot-supported boards (even the old ones with ancient hardware) would be working fine at 1024x768 but 16.8M-color mode. But if there is confidence, please let me know and I would make a new change where the default VESA mode would be switched from 117h to 118h for all the boards.
I think it's worth the risk. a) it's only a default anyway, b) there aren't any ancient boards left in the tree and c) there seem to be few people left that run option roms in coreboot (maybe there'll be more again if AMD keeps their proprietary BIOS forever strategy).