I must admit to a bit of misunderstanding regarding AT and bumping it into MCT.
While enroute, I bumped the levers out of CLB and into MCT thinking I'd lose AT as well and I didn't. The EPR started climbing, obviously, and putting them back into the CLB detent returned everything to normal.
It was as dramatic a shift in automation levels - more of a hybrid change! but it was easily returned to the previous level.
Always learning on the Bus.