Heya Tom. It has, and there has been a bit of disagreement regarding whether it truly should be classified as a middle-pop.
I didn’t think so, because the style seems to be all about being in between the flippers, not merely in the middle of the playfield.
In Carolina’s case, the distance between the flippers and pop bumper is so great that it really doesn’t have any real interplay other than on the way out. As such, I wouldn’t personally categorize it with the rest which are notably different in terms of gameplay.