Can we stop being being conscious of being conscious and still be conscious?
Yes. In Deep Sleep which is the Dark Samadhi.
What then is non-dual meditation?
Being conscious without introspection, without retrospection, without qualia. We move away from the feeling of the feeling of an object.
Does this not precipitate infinite regress?
That is a philosophical question. The answer would be no because of the innate fascination of qualia. Also it is non-adaptive to do so. You will walk into the furniture.
Anyway it’s all consciousness (man).
True but not usefully so at this level of the spiral. Raja yoga employs the techniques of originating consciousness from different chakras i.e. yantra, mantra, asana, pranayama. Experiences are evoked which induce connaturality. That copper beech!