I once tried to swap-in the screen assembly of a Pro1-X into a Pro1. They fit mechanically and connector-wise. The result was that the Pro1 was able to boot into a (working) Lineage recovery, but not into the full OS. I thus assumed the selfie camera was different.
Of course, the top half of the Pro1(X) includes more than the (touch)screen and camera. There is the indicator LED, the ambient-light photodiode, a speaker and (I guess) a mic for handheld audio. But somehow I had assumed those were analogue devices that could not cause a crash upon boot.