I don’t know it, but I suspect, that the UEFI BIOSes of all Intel Chipsets from 7-Series up are UEFI v2.3.1 compliant.
Since I actually neither have a Z77 nor an X99 Chipset system, I cannot answer these questions.
You may have to find it out yourself, but I am pretty sure, that the X99 Chipset will be the better platform for the Intel 750 PCIe SSD.