I guess it wouldn't be too difficult for someone (with better Maxscript skills than me) to write a small script that translates scale sizes to light dimensions..
Having all those custom scales wouldn't sit too well with me, from a scene organization standpoint. For example, one could have two lights that are instanced, so same Intensity and Length/Width, but produce different illumination because of custom ScaleX/Y values.
Having said that, I too would like to know if it would be totally ok to scale lights and not worry about artifacts or other issues. Wouldn't you run into issues if you created a light of 1cm by 1cm with an Intensity of 1, and then scale it by a large value to have it illuminate a large scene?