I believe that it would correct it. I understand that the controller is what sends the signal for the dimming circuit of the ballast. If you were to bypass that and give it a signal of your own via a pot or just hardwire it to full on. This could possibly fix that situation. I understand how frustrated you are with this thing I would be pretty bitter about it as well. It sounds to me that it is a possibility that the controller is not sending the correct signal to the ballast to go full on.
Ok I'm going to give it a shot. M's are on and momma's making me a burger with a fried egg on top to put me in a good mood. After lunch I'm going to dig into this thing and rewire the T5's to separate them from the controller. I hope this works, it takes about a half hour to tear it apart, and another half hour to put it back together. If it doesn't work I'll be tearing it apart again once I get a new ballast, but if it does work I'll save 40 to 60 bucks. Wish me luck. Haha.