areaportal window

Prefab list as of v1: Areaportal windows Black White Spawn Points 16 Any Red Blu 12 Any Red Blu Stairs 64HU 128HU 256HU

Is this... not allowed? I know that if you have, say, two doorways on the same wall and they both have areaportals covering them, they'll be merged into a single one when the map compiles. But if one of them, for some reason, is a func_areaportal_window, does this cause problems? I ask because...