I've always been relentless with these kind of feature requests (how many users actually would use it and would it be worth the large effort to make it happen?). However more and more people requesting features related to storyboard and play interaction tells there is depictable demand.
First thing you guys must understand that currently the storyboard code is not a real scripting language, all the code is just preprocessed and loaded into a sprite transformation timetable (thus heavily optimized). This happens both when loading a storyboard inside the editor and before play. Thereby all storyboard changes you make inside the editor alters the sprite transformation timetable and the editor generates new storyboard code based on this table when saving.
That means if we allow conditional code we no longer can preprocess code and we would need a real script interpreter active during play. Additionally some large scale changes will have to be made to the editor related how to visually edit the storyboards.
Just put that out there to show that this feature request (or its cousins) is not simply added.
I might want to work on this next year but no promises. More than enough other things have a higher priority.