"Ultimately you will end up shooting 4 around with +7 degrees tilt (up) and stitching these images. The reason should be self explanatory. With this slight tilt up you will totally close the zenith hole/star and thus take the requirement of shooting an up zenith shot out of the equation."
I agree with that, but I just want to make sure that I have NPP set correctly so that the stitching process will be smooth and the end result will be worth it.
Here is another NPP setting. This time 4 around 5 degree down. You will notice the tile looks good except for one spot.