Talk:Absorption/@comment-82.14.66.135-20141224133738/@comment-26574369-20150811154239

He does. Like when he's testing out his synthesis he puts "vulnerability to light damage" onto an item and then checks to see if he can still use it himself. He activates it, gets a sun burn, and turns it back off.

So yes he's been shown to be able to turn any ability on and off at will.