For me, Plato's cosmology has zero correlation to anything Ron did or thought. I tried to make a correlation, but it was a pretzel. Plato's universe has no time because it is made of forms. Forms are not made of matter. They are immaterial. Thus no time. Time is an illusion. Time contains pictures and the pictures themselves (even the physical world) are illusions for Plato. But pictures and time have nothing to do with reality (forms). Forms have nothing to do with pictures because pictures would also fit the definition of matter.
So maybe that helps. The reactive mind is made of pictures, regardless of whether we admit that the whole is related to time. The reactive mind does not exist. Has nothing to do with Reality. So living one's life trying to great rid of nothing is sort of like how Plato describes life on this ball called earth: an illusion. Not real. Pictures are unreal = made of time and matter. Matter and time are unreal = pictures. Only forms are real for Plato. As I said, Plato's philosophy is wrong quite often so don't blame me for spelling it out. Plato would just view the reactive mind concept as words humans tell themselves. Notes and thoughts. Matter.
In the world of pretzels and strait jackets, of course the reactive mind is real.
If Hubbard had stopped at the point of saying something modest like humans can create scenarios in their minds, and sometimes they can make such scenarios come into reality for others. Then he'd be in less trouble. Or if he said, we can shift how we feel, change the position from which we view something, that would also be more modest and better than 'as-ising' which concept suggests a violation of physics.
I can't answer more since what I have just said is my view of the entire subject. I've already become extremely boring talking about this. Getting too long-winded etc. There are no other details I can finesse on this one. (And all of this is just my opinion so no harm done if you or someone else wants to disagree.) But my question is, why stop at one spiritual dimension? Why not an infinity of them? Why just the couple physical + spiritual world? Why not multiple parallel universes? Why the hierarchical setup where there are two worlds and one is superior to the other, i.e., the spiritual world trumps the material? Why not lots of worlds that are different without one world being able to lord over another? the Theta universe BS is just BS as far as I can tell.
In a physics where nothing can be created or destroyed, it's hard really to buy into banks that can be as-ised. It sounds like something Hubbard dreamed up in third grade.