@kratkale I don’t know what you are asking.
what’s nvme1n1 this boot cycle, might very well be nvme0n1 next cycle.
While you may see some level on consistency, SERIAL based devices (PCI, SATA, USB, etc…)
All load their identifiers (/dev/sda, /dev/nvme0n1, etc…) on a first come first serve basis.
What’s /dev/sda1 this boot may be /dev/sdb1 next boot and so on. There’s 0 method to guarantee they will always get the same label which is why many Linux machines use a UUID for the fstab file now instead of their path names (which was used for a long period of time).
FOG just returns the list of devices lsblk sees in the order lsblk sees it.