Surface mounted pointers should work fine and give more accuracy than sticks etc.

I wrote vertically but I saw in my mind nose down. For experiment perhaps a chair is sufficient mount for a model. Wings against handrails and pillows stuffed around the nose to keep model stable. When the distance is three feet and reflection multiplies the deflection 5 decrees equals 6,34'' in the wall. Using Tangent:
10 = 13,1''
15 = 20,8''
20 = 30,2''
25 = 42,9''
30 = 60,4'' which starts to bend to the floor and roof.

Perhaps stamp size of Mono-kote "mirror" is good for reflection and bottom side they won't ruin the design. Advantage using mirror is that it shows if there is angle difference between surfaces facing to the beamers, which is not so easy to find with surface mounted devices. Their accuracy can be verified mounting them first to the same surface and next turning another upside down.