It is very disappointing that this option is not available for current motherboards.
There was a good solution in the old LGA1150 Z97-Deluxe boards, where you could choose to set either M.2 or SATA in the BIOS exclusively. This gave the possibility to have two isolated systems, one on SATA and the other on M.2 disk. It was physically impossible to have access to SATA and M.2 drives at the same time because they share the same bandwidth.
It's a shame that ASUS doesn't make this option further.
I would like this option on my Crosshair VIII Hero (Wi-fi) - I use Ubuntu to clone my NVME as a backup and I like to disable the other one to avoid confusion of which is the source/target if there are extra drives.
Definitely agree with the others saying it shouldn't matter why, it should just be an option and those who don't want don't need to use it
I agree!! Mine is a Strix with no option for that but it would be nice to have for instance when I'm installing multiboot and want to make sure I don't inadvertently write over the wrong disk. Fingers crossed Asus will listen and act.
Thanks for mentioning this (and putting up with one social nerd's ignorant comment).