Most projectors are throwing at some angle. For example, the bottom of the image is further away than the top is. Like my projector lens is in line with the top

Most projectors are throwing at some angle. For example, the bottom of the image is further away than the top is. Like my projector lens is in line with the top edge of my screen, and works just fine. Most projectors have some way of compensating for this skew. I would think if you mounted it vertically on a wall, it would be fine. You would still want it centered horizontally though.