Make an even smaller one for a star, and it can be your artificial star to do star tests to check for collimation
I don't really understand the reason for this test really either.. I suppose it could be used to check optics in a small way, or an eyepiece when comparing eyepieces.. but any target during the daytime could do that.
I might try it though, and take an avi.. it might be the best saturn image I get when I don't have to peer through bad seeing