I've downloaded the last integrator toolkit (6.1.6), and when I try to create the custom bios, I have these issues:
With the command: ITK6.efi -b -x myBios.bio -il myLogo.jpg
There was an issue creating/ opening the .BIO: myBios.bio.
With: ITK6.efi -b -x myBios.bio -ic -il myLogo.jpg
There was an issue getting the current BIOS custom settings
There was an issue getting the current custom settings
There was an issue getting the BIOS settings data
I use a FAT32 USB, and a NUC6i3SYK
There are known incompatibilities between the FAT32 and clone file systems created on/by Linux- and MACOS-based systems. Their tools make claims about being 100% compatible, but they simply are not (no arguments; this is a fact, not an opinion).
It is recommended that, before you use any new (or state unknown) USB flash disks with the NUCs, you should reformat them, on a Windows-based PC, using the FAT32 file system, with the Quick option disabled.
I used Ubuntu...
So, I will install Windows to make the USB, and the jpg image; because I have problem with the image too (made with Gimp...), but this issue is documented.
Lot of fun in perspective