Yah, that's the question: Is it possible to use the M44 cam sensor on an M42 engine that has M44 sprockets installed?
To answer this, it seems there are 2 items to be resolved.
1. Is the location and mounting arrangement of the M44 sensor the same as the M42, or can it be adapted?, and
2. Does the M44 sensor produce the same signal as the M42 sensor so it can be interpreted by the ECU (or whatever box it is that uses it)?