I have an elan 7n but have never tried IR film in it. Indeed, the elans have an IR sprocket counter which will fog IR film. However, depending on how bright the IR illuminator is, it may or may not fog only the edges and not the actual image. The best answer is to give it a try once and see if it works.
It will fog the sprocket hole area, and about a 1mm strip along the edge of the actual image. Go ahead and shoot IR. A very minor crop will take care of it.