I measured spectra of IM/MN photosensors.
Figure 1 shows the result.
There seems no serious problem.

IM V3 photosensor have larger noise below 10 Hz but is is coming from ADC noise (klog20902: it says noisy channel is IM V1 but it is wrong. Correct noisy channel is IM V3).
Also, IM H2 have slightly larger noise below 3 Hz but I could not confirm where it ccomes from.
However, IM photosensor has never used before, so it is not problematic.