As to your aside: the 2mhz 8086 claim was about UEFI Shell - which is as close to native (usually 64bit) UEFI code as can be. That, and the "UEFI binaries are

As to your aside: the 2mhz 8086 claim was about UEFI Shell - which is as close to native (usually 64bit) UEFI code as can be. That, and the "UEFI binaries are unportable" bit really indicate that the author doesn't know very much about UEFI. (Aside of my own: there are typically at most two places in x86 UEFI where you can find 16bit code: first at the init vector, where it sets up the system to move to 32bit - and then 64bit modes - as fast as possible, even before initializing DRAM at all. The other place is the CSM, which provides the legacy BIOS interface, if necessary)