Hi Trevelyan, what version of 3ds Max are you on? The script works on Editable Polygons only, make sure you are not trying to run it on Editable Meshes, otherwise it won't do anything. To make a quick test: create a sphere, convert it to Editable Poly, select any face close to the equator (it is easier to spot the effect)…
Yeah, I'm interested in this for the same reasons, now that I can use edited vertex normals in UDK, I'm doing it all over the place. But yeah, Max really isn't so hot for working with them, not only is the Edit Normals modifier kind of shitty, but max tends to mess up the edited normals alot depending on what you do to…