What method/pattern do you use if you have a monopod using the Nikkor 10.5 mm ?

I use a Nodal Ninja Ultimate R1 on top of the monopod.
I do the method of Klaus from the Kolor Forum, pitch -15° to reduce the nadirhole.
But rotating 90° up for the zenith does not work correctly because it does not rotate around the nodalpoint. I always get bad stitching results that way.

Do I have to freehandshot for the zenith and nadir ?
Maybe I missed some basics ?

Maybe the Nikkor 10.5 was the wrong decision ?

I've a Nikon D5100.

Kind regards
Alain