A camera that has split dimensions for its position array will only export the X value using the Maxon C4D Exporter.
I have tested collapsing the position and re-exporting and it will bring in all dimensions of the camera in C4D despite it being the wrong animation due to collaping and losing unique tangent handles.
I've tested this with the latest After Effects as well as the most recent Beta (23.3.0 Build 38)