You seem to be saying that you are upset because external devices are not supported for UEFI secure boot. I believe that this is intentional. The concept of secure boot is that the BIOS is certifying to the O/S that a chain of trust exists for all devices. I do not believe that it can make this claim with an external device in the picture; it could be replaced at any time by anybody. You will need to choose whether you want an encapsulated secure system or an open insecure system.
Just my opinion...
Hello Scott, thank you for your response. Problem solved downgrade from
BIOS rev. 66 to 64. I use linux system with LVM array disks and there
are already correctly seen as UEFI Secure mod.
Have a nice day