Yes, I too would like access to control of IR in a viewport. The cumbersome way it works now is actually the only reason I'm not using IR in a viewport. A simple double click in the viewport to (re)start and stop (freeze) would do it without any buttons.
And yes, I know there are ways to make this myself, but I can't see the logic in Corona wanting to be "user friendly" and "easy", yet lacking direct access to the most used controls (for me at least).
Hope this will be looked at in nearest future :)