Yes with FE lenses the NPP varies with angle, I have two settings recorded
for my Sigma 8mm, 45° - 8 shots and 90° - 4 shots around, there being 11mm
difference between the two settings. Rectilinear lenses are much easier to
setup!  Yes you need to do the setup with camera and lens in the actual
positions you will use, its not just angular rotation that is important but
also alignment to the axis of rotation that is critical.

Do also consider with FE lenses that going for the minimum number of shots
may not be the best solution, the difference between taking 3/4 and 6/8
shots around is pretty small in time 10-15 seconds, however having
additional shots means that ghosting and movement is much easier to resolve
and can save you hours of work in post processing!  I rarely use the 4 shot
+ Nadir option, much preferring 8 shots + Nadir with the Sigma 8mm.