That's a good question me!
Happy for me ;o)
The board does support two video interface at the same time I just discovered by tweaking the BIOS.
Don't know the exact configuration item but will revert back to you later on, in case others then me have the same support question.
Well I (me) figured it out.
In the BIOS go to Configuration, Video, IGD Secondary Video Port and set this one to "DisplayPort".
That does the trick by me, me.