Selectable Primary Video Out Gpu, Possible?

[Raduq91]

Can a primary video out setting be implemented? had it been tried/tested to try to load the vbios from non primary video out? ex gpu in second slot or igpu based on VEN DEV id or pci path(or acpi path). Or/and maybe ignore/hide the primary video out that is set in bios and seabios will try to load and init what is available?

Context, I have an intel z690 platform that has the option in bios to set primary gpu from different pcie slots. Same vendor on amd x870e lacks this option.
As additional info there is "diy egpu setup" program targeting laptops to modify primary gpu/video out by manipulating the acpi I think and then chainload windows bootloader.