My argument doesn’t necessarily require a temporal sequence. The known is known by the knower, and then the knower is known, simultaneously, if you must (although I would disagree with this ultimately). Similar to how the Father is primary and the Son is secondary, even though the Son isn’t begotten in time. Therefore, knower and the known can be argued to arisen temporally simultaneously, but ontologically, the object is known before the subject, and the subject is then known by reference to the object (this makes sense, since the self is immaterial, and so is understood in analogy to material anyway).
However, time is an objective reality, at least in part, otherwise dimension, extension, velocity, Carbon-14 dating, the age of the universe, spacetime, etc. make no sense, so there isn’t a problem, at least for the reasons you give, to say that there is a temporal distinction as well.
The point made by Thomist epistemology is that consciousness is not a closed system that somehow must find a way out of itself and into the world, but rather that the self itself presupposes reference to something non-self. Because of this, the external world is known before “I am” is known. Even if the subject is known ontologically simultaneously to the object, it still demonstrates that we can’t know the subject without reference to the object, and is thus sufficient in demonstrating that if we can know the subject, then a fortiori we must know the object (not completely, mind you, but that we can contemplate the object’s essence). We can know what the object is too, and not just that the object is, if we can know what the subject is.
And since we can know that the object is, and what it is, this refutes any rational basis for solipsism, along with the argument against the"deceiver" arguments.