This is gold dust. So in summary:
1. 2.4L engine has same exhaust flanges and diameter of initial exit so an aftermarket manifold from 2.0 will easily and neatly bolt onto a 2.4
2. Even without a tune the torque dip is nearly eliminated, which means the 2.4 is a very similar engine to the 2.0, just a bit more displacement. That is probably expected but proven now.
3. The 2.4 factory manifold has wider exhaust runners to and from the cat end, so likely to make more power on a 2.0 car as well, if fitted. This will be covered in their next video, so lets see what happens.