Apple's own maps app has simultaneous drag and magnification

I see that it says that. But the fact still remains that it is possible to create a Transform that disagrees with itself. This test should never fail: func testTransform(A: Transform) { assert(A.rotation.angle == Transform(matrix: A.matrix).rotation.angle) } Something strange is going on internally with RealityKit's Transform. There must be redundancy in Transform's state that leads it to disagree with itself when passed an unnormalized quaternion.