Exhaust air and supply air one above the other?

I would then do it the way you marked it. So leave 3 m distance between the two outlets. I wouldn’t like them directly above each other, but I have no expertise on that, I would just have a bad gut feeling about it.

I saw yesterday that one of the neighbors has the outlets stacked on top of each other. I had never seen that before.

The controlled residential ventilation main unit is installed in the attic with us.

A breakthrough is then made at the very top of the gable and an element is inserted there. This is for both supply air and exhaust air.

The exhaust air is blown out "straight ahead" and the supply air is taken from a downward-angled duct. As mentioned, the whole thing is one component.

... I just wouldn't have a good gut feeling about it.

I feel the same way.

Supply and exhaust air can be located on top of each other. However, there must be a minimum distance of 2 meters between them. Since there are also connection boxes where both are integrated into one, there are no problems in that case.