I gave up and used usb stick to fire bootloader, do you know if this infulence performance?
You probably lose a micro second or two, during boot, by loading the bootloader from USB, instead of SSD.
So I won't touch this anymore, thanks 
Sorry for reviving the thread but I have the same problem. I used EFI-enabled archive with DD. I see the partitions on the disk but it doesn't appear in the Boot Menu of the device. Any idea why?
Secure Boot is disabled.
EDIT: I used DD to write the archive to the USB stick. Lo and behold - it booted off the stick and loaded OpenWRT from the SSD...
EDIT2: I actually used the tip with rEFInd: LINK. It works!
Not sure why standard boot loader doesn't work...