First results of analyze MOV-(gdsmux)->MKV-(mkv2vfr)->VFR
wide ipd test cam1 t02.vfr:
# timecode format v1
Assume 23.976
0,552,29.9518
553,553,31.2500
554,1105,29.9512
1106,1467,29.9471
1468,1468,31.2500
1469,4109,29.9498
4110,5111,29.9516
wide ipd test cam2 t02.vfr:
# timecode format v1
Assume 23.976
0,2106,29.9498
2107,2107,14.9254
2108,2341,29.9501
2342,2342,31.2500
2343,3873,29.9497
3874,3874,31.2500
3875,4266,29.9511
4267,5109,29.9478
As you can see base framerate is not constant (intervals with bolded values). It is from 29.9471 to 29.9518 fps.
I think it is not precisely (maybe) because standard is 29.97 fps. I will make another analyze to confirm it.