I agree mindfulness is as you have claimed BTSO, although with AVRT, AV is/are not irrational thoughts exactly. They are quite rational from the Beast's perspective of course. And from my own perspective, AV is my normal thoughts, feelings, images - recognised by me as Addictive Voice.
Still, AV is to be otherwise disassociated from my own thinking, and then dismissed as being un-significant after recognition.