I don't see that as unique to presuppositionalism. I think the defining point for Van Tillian presuppositionalism is whether we must presuppose the self-contained concrete universal in order to account for all of reality, along with the claim that the traditional arguments (and method) are false.
I think those are not as connected as you think. The first point is basically the way I've layed it out before. If Christianity isn't true what (besides non-existentience) would be different in our experience of reality? This is a paradigm case argument, it fleshes out what "account for" means.
If there is a difference than what is it and we can compare reality to the difference to see if it's that way. But that's a transcendental argument and that contradicts the critique of TA'S in general as a method of argumentation. You can't critique the method only to turn around and use it.
If there would be no difference than that is autonomy in being, knowledge, and ethics. It makes Christianity superfluous to reality, ultimately. Either way Van Til wins, that's the dirty little secret of criticisms from other Reformed Christians that they'll fall in one of those boats.
Now the second point can be summed up like this. If the apologist falls into the second option, either knowingly or unknowingly, and then they try to build their arguments (assuming that) than what they are arguing for is not Christianity but something else.
Now is it possible for a Classical apologist to admit option one and still insist on using and developing classical arguments with that in mind? Sure, Van Til said that the classical arguments could be reformulated along these lines, whether or not his formulations are acceptable to the classical apologist (or are sound) is beyond my interest so I never thought about it.
But if we take his general criticisms and pull them back a bit to show that it's possible to avoid the problem I (working from his thoughts) developed, than fine. Then it's more of a warning of what not to do, instead of an inherent problem in CA.
Now I know some may not know what a paradigm case argument is so I'll explain. A paradigm case argument (PCA) is a type of argument used against extreme skeptical claims. The Matrix argument is kinda the classic example, the claim has been made long before the movie (or movies in general) existed but for contemporary people they can use it to latch on what's going on. How do we know the world around us isn't just an illusion or matrix type reality?
Various answers have been given, common sense realism is the best but it's a positive argument never the less. A better question is "is there really a problem I have to solve there?"
Taking this angle one could argue that the skeptic has the burden of proof here. They need to demonstrate how reality would be different if it's all a Matrix type illusion or not? They generally say that there would be no difference. Well if there's no difference than I have no reason to abandon my belief in reality being not an illusion and have no worries about being stuck in the Matrix as the result of machines. Great movies though.