It's the classical problem of a standard that nobody actually follows. Every UEFI firmware that I have come across has behaved differently.
My current laptop has an UEFI implementation that only boots from a hardcoded path in the EFI partition. You guessed right, the path of the windows 8 bootloader.
The UEFI in my home server overwrites the UEFI boot manager list every time you save & exit the configuration tool.
If I remember correctly, the UEFI implementation of a MBP that my friend and I tried to make dual boot Ubuntu required a blessed HFS boot partition for every OS.
I'm really biased against Intel processors now because of this - I endure my distaste for how horribly documented and black box their parts are, but the fact their firmware for going on 6 generations has no documentation to enable coreboot on these boards drives me to AMD.
Yea, they don't open up all their stuff, but if you dig around you can usually find a board on most chipsets that works with coreboot. That gets my purchase. Plus they are doing good work with the radeonSI mesa driver, even if they still pack binary power firmware with it (I've read a few articles decompiling and inspecting it to know it is mostly just init command code to start the hardware).
My current laptop has an UEFI implementation that only boots from a hardcoded path in the EFI partition. You guessed right, the path of the windows 8 bootloader.
The UEFI in my home server overwrites the UEFI boot manager list every time you save & exit the configuration tool.
If I remember correctly, the UEFI implementation of a MBP that my friend and I tried to make dual boot Ubuntu required a blessed HFS boot partition for every OS.