Ken Wilber is a mixed bag, (much like Jordan Peterson). Much of his work is very insightful, but some of it goes off the rails.

Having thought about the Four Quadrants for years, I've come to realize that it is basically Kant with the addition of one 'quadrant' which is exterior collective. This was Wilber's way of explaining Foucault and Power. I've come to believe adding "Its" is incorrect, and it is better to stay with Kant: subjective, objective, and social. I talk about this here: https://jaime-roberts.medium.com/the-hyperreal-world-of-postmodernism-93f1130f55f0

I believe this fourth 'quadrant' is something, but not what Wilber thinks it is. I explain the system here: https://medium.com/original-philosophy/a-brief-theory-of-everything-interobjective-ecologies-45d0a29cf9e0

Wilber is a good starting point, but one should move beyond his theory as it is a limiting meta-narrative, and far too seductive. I think Wilber was very popular in the 1990s (or 2000s?), but his popularity has declined as people see the limits of his theory.