Does the TO belong to Thelema?? I think wikipedia says kinda yes, but I really never trust Wiki.
Typhonian-ism and Maat magick, are both conjoined subsets of modern Thelema (which in itself is a subset of the hermetic magick tradition, lol).
I can't say much for Maat (it's ideas outside of Typhonian-ism), but the Typhonian Order, is largely about exploring the subconscious (to extremes way further/deeper than Crowley with his
30 Enochian Ethyr visions)
The Mauve Zone is the plane of existence between the conscious and the subconscious (reality and dream).
While Crowley tried rituals to bring his mind between exhaustion and the euphoria of orgasm, he didn't explore it in the depth Kenneth Grant did.
Essentially, the Typhonian Order focuses on this, the collective Aether (with all the sacred texts), kabbalah and sort of the blurring between reality and imagination. This is also why Grant decided to write about Lovecraft with such conviction in his books.
Another aspect of what I just mentioned, is a similar idea in Kabbalah itself, to do with exhausting the connections between all things till a kind of "mental breakdown" - which results in a very strong fulfilled feeling of enlightenment.
Kenneth Grant explored some great ideas, his books can read in several ways but they
are partly supposed to put you in a daze. I guess, the more you understand, the more your subconscious reacts.
In Chaos Magick, this blurring is sort of taken to it's inevitable conclusion with less intellectual complexity.