You give me a direct quote or pointer from PON (with page no.) that can help an anxiety sufferer overcome their panic disorder? I'll tell you why it won't alleviate or treat panic.
The reason it forms a positive feedback loop is that the sufferer is perceiving, input cycle, of the output cycle (SNS) as alarming or dangerous...
When you 'inhabit your body'
as is so often recommended by Eckhart, then there is no more thought, hence no more feedback loop, hence no panic disorder ...
When you remain in presence there can be no anxiety and no panic Ashley, because anxiety needs thought to fuel itself ...
When you put your attention towards your inner body... you don't stop perceiving all of sudden because your are in the now.
Furthermore because it's impossible to stop perceiving....thoughts will arise spontaneously at any moment. The little voice in your head gives you clues to the "output cycle" of your perception.
If someone who is suffering from GAD started to place their attention towards their inner body, there would be a high probability of having a panic cycle... because they're more likely to interpret/perceive bodily sensations as dangerous and unwanted than a person not suffering from GAD.
It's not the attention towards the inner body that miraculously stops the panic, it's the understanding that you need to stop mis-perceiving unpleasant sensations as dangerous & something to be avoided. The moment a sufferer adopts a positive affirmation that these usually unpleasant feelings are normal and acceptable during their exposure... the positive feedback loop is de-activated... and the recovery from a panic cycle can start.
Remember No one can ever turn off the little voice in their head, because that is an output cycle of perception. Even Eckhart Tolle has a stream of thoughts.
The only way we can alter our thoughts is by changing our perceptions, but we can't turn those thoughts off.
The most effective way to alter mis-perceptions about something is through direct exposure. If you had an irrational belief about that thing... exposure should set the record straight.