I have both. However, I haven't flown the U Can Do, only the Twist. My Twist has an Evo .46 in it. Last two flights, I had engine probs where at half throttle (was going vertical to do a stall spin), the engine quit and I had to dead stick. Man, it floated down like a parachute.
Best landing I've ever done!
Anyways, mount your current .46 at the end of the engine mount as the Twist builds tail heavy. Its has a 1 inch CG range. Forward at 4 inches from LE and to do really cool 3D stuff, tail heavy at 5 inches. These values are in the manual. My Twist, I had to add just about 6 ounces of weight in the nose to balance at 4 3/8 inches.

Dave...