I have come across some academic papers on SPD. From what I read the case of SPD as a single personality disorder is not very strong.
Some papers even sugested that it shouldn't exist as a diagnosis.

Anyway, people classified as having SPD may fall into two categories. The more avoident ones and the more schizotipical ones.

What is your opinion about this? And in what category do you think you belong?

I am sure I am not schizotipical. I am a little avoidant.