Lukas Ruzicka composed on 2021-03-30 13:22 (UTC+0200):
*On computers with dual video cards (or with external video output) the system must be able to display the video content on each connected device.
Above to me is rather ambiguous.
Laptops generally have one external output only.
Traditional PCs only have external outputs. One or more may be motherboard outputs. One or more may be on one or more graphics "expansion" cards. A PC may have both expansion and motherboard outputs.
Docking stations may be employed, confusing the concepts of outputs even more.
Better would be language of connected displays in lieu of video outputs or "cards".
If the criteria were to be implemented, as others have mentioned, blocking would have to be limited to two displays, however connected, on account of limited facility to test more than two, and the many possible permutations of connectivity.