I suppose my definition of a momentary push button would just be a button that unlatches when the user releases it. I don't think it would be too difficult to script a button in Perspective to perform a jogging function as you describe, but maybe I'm oversimplifying it.
Personally, I just love the mobile design aspect of Perspective and it can do everything that I imagine an average user would need. Just my opinion though , and of course, I'd need some information about the average user to validate that claim. Thanks for the info on some of the shortcomings, though!