Studio Mode - Possible to add a hotkey for a Preview -> Program transition?

[ssc]

As per title, is there any way of adding a hotkey to increment/decrement the transition bar between Preview and Program?
Aka manipulating the last element screenshotted below - ideally looking to use a T-Bar if that helps!

 

[AaronD]

I've wanted that too on some rare occasions. Leave a fade transition in the middle for a while, for a half-transparent view of both scenes. But I haven't found a good way either. I tried once to just drag it with the mouse and leave it there, which does technically work, but it's nowhere near smooth enough. So I'm interested too, to see where this goes.