by mac3uck
The answer from Lookout Games is:Man muss den Diagonalzug durchführen können. Es geht nicht, auf einen Teilvektor zu verzichten.
Which means:
"You have to be able to make a diagonal move. It's not possible to renounce one part of a vector."
So based on that feedback, I conclude that the board do limit your move, but only if you're possible to do proceed the exact kind of movement printed on the building card.