Same thought.

The way that almost all UAP sightings describe craft that "defy physical limitations or understanding of aerodynamics" is kind of a hint.

The UAP isn't the whole thing, it's the but that extrudes into perceivable dimensions. Like the top of a shark fin breaking the water.

The fin isn't the fish, it's the bit we see because we don't live under water.

Interdimensional also allows for breaking "the rules" of speed and time in 4 dimensional space, because they can dip in the way you'd dip your pinky into a fish tank.

To a fish, when you put your hand in a fish tank, a strange five legged creature has just descended from heaven.

You pull your hand out of the tank. Poof! The five legged creature disappeared!

You put your hand back in the tank behind the fish. Poof! It's back!