Yes, of course this works. The problem is i am trying to combine keying the intensity (what you've described) with using intensity curves (a curve that represents a light's diminishing intensity over distance). They both show up in the graph editor, and from what I've experienced can only be used one per light as they occupy the same channel. If you know of a way to combine them, please let me know. The workaround I came up with is keying light's color instead.