Is bifucation possible or required for my setup? x99 deluxe ii

Hello all. I have a x99 deluxe II with a 40 lane CPU. I currently have 3 x8 GPUs and a x4 usb controller. I will be moving the USB controller to slot 2, so that will not be occupying pcie lanes (instead it will use PCH.) I would like to then use a mother/daughter card setup to install 3 x4 thunderbolt cards. Slot will be the likely candidate for the mother card.

Slots 1 and 3 are the only slots capable of x16. this means I will have GPUs moved to slots 3,4, and 5, all at x8. slot 1 would need to run x12 to three x4 cards.

is this something that is possible with a custom bios? or is it even required? Im not sure how the q-switches affect the pcie lanes.

thanks.

Plenty of info around to X99 bif settings/mods, search on the forum.

honestly I have attempted that, and read quite a bit, but its quite a bit over my head.