Human agents are not ever suited to make decisive choices to conclusively reject God
While it is certainly true that impaired human agents are not suited to make decisive choices to conclusively reject God, that’s an incomplete truth.
Per my understanding of what Aquinas meant by “comprehend” vis a vis the light of glory, in the beatific vision each will fully “behold” THAT we’re interminably united with the Trinity, operatively & perichoretically, but neither WHAT that unity is quidditatively nor HOW it is distinguished (in/finite) modally, speculatively & participatorily.
So, even once gifted the light of glory, because we are finite & God is utterly incomprehensible, we’ll remain forever nescient & in infinite potency, so always potentially growing via epektasis.
And it is precisely because we are forever nescient that – not only are our acts always essentially nonnecessitated, but – none of our rejections of truth, beauty & goodness could ever be total or definitive.
Ergo, human agents are not suited to make decisive choices to conclusively reject God. PERIOD. FULL STOP.