The problem with Guenon and Neo-Advaitans is they explain a false conception of monism, one which is stagnant and reminiscent of a featureless blob. This because they treat the imagination and even processes as illusory. Let me begin explaining through the use of a powerful metaphor.
Let me begin with the true genuine kind of monism. This was experienced by a few like Heraclitus, Dharmakirti, Hui Neng, Joshu, some Daoists, Bergson, and J. Krishnamurti:
"The whole universe is one body that breathes in fractal complexity, which includes the unreal, the imaginative and fantastic since the total is all, and you cannot separate the motion of breathing from the body, since there is only the motion occurring. The imaginative in identity with Infinity is more real than the real."
As you can see, this is pointing to how real creativity, true novelty, has its source in the primordial Infinite. This monism has no "bottom turtle", underlying ground, and instead points to a kind of Heraclitean flux.
Now, let's see what Adi Shankara, Guenon, and other Neo-Advaitans argue.
"The whole universe is one body that excludes distinctions, the imaginative, and fantastic since they are illusory, and the Absolute is an aspatiotemporal oneness."
This is a kind of "lobotomized" vision of the Universe. One where novelty, MIND, and imagination are not important being seen as ultimately illusory in a world of One gray substance.
This fundamental distinction between monisms among the world's traditions has been ignored by the Traditionalists like Guenon, Evola, and more. I think this is because they did not spend time studying thoroughly or talking to enlightened figures, thereby losing all nuance. Even when the mind is pacified, contemplative, wise, and so forth, there is still a kind of singular flow of novelty, a moment-to-moment Oneness where the flower simultaneously flourishes and wilts. To claim there is no flower, no motion, and just a featureless blob is, quite frankly, retarded.
I, as the founder of Neo-Zurvanism, am already a better thinker of Guenon, but since I lack there connections he has, I will never gain the fame or recognition he did.