[NOTICE]*If your MEFW version is lower than 15.0.23.1706. Please be sure to update ME firmware R1FRN18W(15.0.35.1951) first before updating system firmware. Or else the system might crash.
Thanks for the hint! The BIOS has been already updated to 1.20 by the service team. The ME firmware versions are both marked as testing, so I am thinking, it might be better to leave it the way it is…