Dont think so, bioware developers dont know how to do it,i mean lets face it,if they did we wouls have this option now.....
They managed to make the hoods disappear when the robes are worn by Twi'leks. I'm sure they can figure out how to make that into a toggle. It's just a matter of time and with F2P coming up I'm sure it's something they are working on.
I think the main thing holding it up is, this time they want to do it right.
With the Twi'leks, it just removes the hood altogether. But what they want is for the hood to appear in the down position. In order to do that they need to do new artwork for any robe that would use this feature and that's a lot of work.