Mine is perfectly flush on 16 Pro.
However I noticed the official apple cases cause a slight hump with the "button covering a button" solution, in fact the first case (grey) the side of the case actually protruded out a very noticeable amount where the camera control button is. I swapped it for a different one (green) and it wasn't as bad but still noticeable. But the button itself is completely flush with the frame.
Something weird on mine, I think the speaker holes were drilled about a quarter of a millimeter too high in the frame, because the speaker holes in both cases didn't line up properly. I wound up going with a peak design case anyways which has an open button for the camera control (I think it looks and functions better), and the speaker area at the bottom is open instead of individual holes for each speaker hole.