At first I was like meh about integrating in settings, mostly since I haven't tried that yet, but after checking out that 2g3g app, I've got to say it's a pretty slick implementation, I think you've changed my mind. Like you I haven't done anything on that end, just some normal ui stuff, but it couldn't be too hard to go through the docs and figure it out. But what about the page for reading the current settings? another icon on desktop? or bury in settings? Of course the frequency and whether smart reflex is active could be shown on the on/off icon, but there should be more of a read out surely, hmm something to ponder anyway. I'll be keeping conky on my N9 anyway.
I guess the on/off function will rely on being able to change frequency back to 1ghz though, hopefully that doesn't end up being too much of a problem.