Find out IC on that, I would say.
I understand what you're saying. I think you don't understand what I'm saying.
Hypothetical:
If "barrier" could only be broken by a psionicist, then you would know that a psionicist broke your barrier.
If what you suggest could be infiltrated by a psionicist, then you would know that any observable infiltration is the result of a psionicist. If you have "deadened" the Way - and someone suddenly ways you - you know that it has to be a psionicist, because in your suggestion, only a psionicist would be able to do that. Sure there might be psionicist ways around that. Eventually. With time and practice. But then you'd have to create those ways to accommodate this deadening skill that currently doesn't exist.
As things are right now though? Adding that one skill, with the ability of psionicists to get past it, would ensure that anyone victimized would know that "whatever is happening in my head right now" is the result of a psionicist and not just some person with super-contact power breaking down your barrier, realizing you're the wrong sdesc, and then breaking off without saying anything. That is the current situation. In your suggestion, that wouldn't be possible UNLESS the person doing it is a psionicist. Which would immediately raise the red "omg mindworm in my head" flag.