Yay, I guess! Well, yeah, I'd go ahead and do what you do. But, I also change toneMapScale further down than I believe you do.
I set it to (according to the Element Viewer, not Motion/Graph Editor) 0.1, and I have a thing in mind where I'll go with 0.01. Why? So I can add Lights myself. (I also do that for day maps, setting the toneMapScale down and adding lights.) To give models shadows. But the SkyBox is so dark... Well, I go find the SkyBox's .VMTs, open them in Notepad++, and add *$color "[10 10 10]"* (or 100, for toneMapScale 0.01). That way, the SkyBox won't be too dark, and the map won't be too bright, though I cast lights everywhere.
The thing is, however, until setting toneMapScale down, the SkyBox is usually overbrightened. And working with lights in the view gives a bit more lag. But that's nothing major.
Eeyup, I do something overly stupid with an overly big cost in framerate for just a slightly better result.