It took them more than a year to go from Prime 3.0 to Prime 3.1. Prime 3.1 just exposed the automation interface to users (it already existed, but only internally for PTC developers). More than a year, for that! It is slated to take almost two years to go from Prime 3.1 to Prime 4.0 (and we are not there yet, so it could be longer). Prime 4.0 adds performance improvements (GUI only, not math), areas can be locked and worksheets protected, copy and paste finally complies with Windows norms, and you can wrap equations. That's it, after two years! They dropped the new plotting feature from the release, presumably because they still haven't managed to get it done. They say Prime 5.0 will be released a year after Prime 4.0, with the new plotting, "math engine refactoring" (whatever that means!), and "other stuff". Controls, and especially scripted controls, would be a big project, so given the glacial rate of development I wouldn't bank on getting them in Prime 5.0. We still won't have text styles, custom margins, hyperlinks, and many other basic features in Prime 4.0, so they will be (or should be) first on the list. So maybe you have some hope of seeing them in Prime 6.0, which means not for at least 3 years.
By all means vote, but by the time controls actually happen it will be lost in the mists of time.
