Is Z270M Extreme4 support Bifurcation£

Hello:

In Z270M Extreme4 Spec page describes:
3 x PCI Express 3.0 x16 Slots
PCIE1/PCIE3/PCIE4: single at x16 (PCIE1);
dual at x8 (PCIE1) / x8 (PCIE3);
triple at x8 (PCIE1) / x8 (PCIE3) / x4 (PCIE4))*

Is PCIE3 supports bifurcation to x4+x4 when in dual mode?

Thanks!

Thanks for your reply.

I want add nvme card in PCIE solts with Z series motherboard.
For example ASRock ULTRA QUAD M.2 CARD, but its motherboard support list shows only X299 X399 can support it.

As I known, Z370M pro4 can support PCIE bifurcation too, but there is no official description.
Does ASRock have any PCIE bifurcation support board list like below?

Compatibility of PCIE bifurcation between Hyper M.2 series Cards and Add-On Graphic Cards