Hello akjuxr3,
as you seem to have a SeaBIOS issue, did you try the SeaBIOS mailing list? Might be easier to get an answer there.
I don't use SeaBIOS, but have a guess: The integration of SeaBIOS into the coreboot build system is not meant for anything but the simplest configuration. In your case, coreboot probably adds a SeaVGABIOS with a generic name in CBFS (i.e. not named after the Intel PCI device). SeaBIOS would run that by definition. So there's probably no bug at all.
Maybe you can configure SeaBIOS to only run the option rom of the primary VGA device? then renaming that file could help. Please read the SeaBIOS documentation in any case.
Nico