My mate does'nt on his, he just uses as is.They are impact wrenches so you'd have to dismantle to remove the impact bit.
The ones I've seen have a small air cylinder to move the impact wrench down to the drawbar and lift it back out of the way, I think that would give the drawbar room to move up if there wasn't a hole in the end of the taper.Easy enough to do but if using MT drills, reamers etc you wont want the drawbar in and wrench in the way to remove! Main reason never did it.