Well you say "cherry picking" but there is a good rationale for treating Castaneda's first three books differently from the subsequent ones.
In his interview with Time (March 1973) shortly after he had published his third book,
"Now I'm at the edge, and I have to change my whole format. Writing to get my Ph.D. was my accomplishment, my sorcery, and now I am at the apex of a cycle that includes the notoriety. But this is the last thing I will ever write about Don Juan."
The "whole format" did indeed change after that ... not sharply and suddenly, since the first half of his fourth book is fairly similar in tone to his third ... but increasingly and definitely.
You mention "interdimensional nazpire" and I think that tracking occurrences of the word "dimension" in the books, and the increasingly odd ways in which it is used, would be a good marker for how Castaneda's change of format developed.
If we grep through the online versions of the books for the character string 'dimension':
in the first book TTodJ it does not occur at all;
in the second book ASR it occurs once, but in a reasonably ordinary sense: "When I moved my eyes away from his face and looked at it with the corner of my eye, so to speak, I could perceive his solidity; that is to say, I could perceive a three-dimensional person; without really looking at him I could, in fact, perceive his whole body, but when I focused my gaze, the face became at once the luminous object."
in the third book J2I it does not occur at all;
in the fourth book ToP it occurs twice; first, early in the book, in the ordinary sense, "Although I had no criteria to judge dimensions, I had had the feeling that it was about a foot long"; but the second time, near the end of the book, we have "Don Juan's voice brought forth another dimension to my state of being at that moment."
After that, dimensionality takes wing.
In TEG for example, "The sound of her voice seemed to act for me as a conduit into another dimension, another kind of time" and "Through the exercise of the third not-doing, Silvio Manuel gave a new dimension to our perception of the world around us" and even, "She said that a part of her last-minute instruction was to make me enter into the second attention as stalkers do, and that dona Soledad was more capable than she herself was to usher me into the stalker's dimension."
In TAoD, "the total mood of the dream changed and I would find myself in a dimension unknown to me" ... "the bluish blob of energy was from a dimension entirely different from ours" ... "He and his party were going to fulfill the sorcerers' dream of leaving this world and entering into inconceivable dimensions".
My guess would be that don Juan never actually used the word 'dimension' or its Spanish equivalent, and that where it occurs, it is Castaneda's invention.