iFixit opened four iPhone 18 Pros for its teardown, and on three of them the white plastic frame around the display broke as the front glass came off. The frame is part of the display panel, and it can't be bought on its own. A cracked one means the screen may not sit flush after reassembly and the phone could lose its water resistance. Other teardowns haven't hit the same problem, and Apple has used this frame since the iPhone 15 Pro, so iFixit says it is too early to tell whether this is a fluke.
The new variable aperture has its own repair catch. Its six tiny blades are driven by electromagnets, and iFixit lost one while taking the lens stack apart. The aperture can't be replaced by itself, so a stuck one would likely mean a whole new main camera. Apple sells iPhone 17 Pro cameras for $250 in its parts store. iFixit did find that an external magnet can move the blades, so stuck blades don't have to mean a dead camera.