I updated the bios of my NUC from version 21 to version 25 (newest atm afaics), but I still can not see the bios bootscreen on my tv with my HDMI cable.
The only way i can see it is by using the display port, convert it to DVI and connect it to my oldest monitor.
(My newer monitor is a Samsung but that one does not display the bootscreen. There i use the HDMI output of the NUC and convert it to DVI)