It is important to clarify terminology of structures and states.
As befits the radial approach, I define the stages of development in a dynamic fashion so that each is characterised by the interaction as between an overall (spiritual) state and a holistic structural pattern (which both define the precise nature of the stage).
The state corresponds to a typical general way of "seeing" (that inherently represents the empty aspect) and the structure the phenomenal pattern of what is thereby "seen" (that corresponds to the formal aspect) respectively of development.
In this way all stages entail the interaction of emptiness and form (and form and emptiness).
Though Ken Wilber also employs the terms "structures" and "states" he tends to use them in a manner, which I find lacks overall coherence.
For example in terms of the middle level he would recognise its characteristic state as "waking" and would identify structures such as conop, formop, and vision-logic.
I have no problem with this, as it corresponds with my own approach.
However when he tries to maintain that the waking state supports the structures of several levels (e.g. his prepersonal stages) I would disagree.
What he identifies - in discrete terms - as the waking state, in dynamic terms represents in varying degrees the interaction of the states of all levels (for the simple reason that in dynamic terms every stage is in some measure continuous with every other stage).
Of course it is true that at the middle band, the waking mode will normally predominate (as will corresponding rational structures). However due to interaction with other states, prepersonal structures can operate (supported in turn by corresponding earlier prepersonal states). So properly understood, it is not the waking state that is supporting these earlier structures.
Thus though every stage has its own characteristic state (and corresponding structure), Wilber does not seem to properly recognise this (due to the lack of sufficient dynamic emphasis in his overall approach).
Also when it comes to his higher levels i.e. psychic, subtle, causal and nondual, Wilber over-emphasises the state aspect of these stages.
For example when he says that we can have temporary access to these higher stages he characteristically speaks of them in terms of states.
Then he misleadingly identifies the permanent attainment of their states (i.e. enduring traits) as structures.
However we do not convert states into structures through permanent attainment.
For example permanent attainment of the waking state cannot be directly identified with the (phenomenal) structures of the middle level.
Certainly the waking state supports the structures of this level (e.g. conop, formop and vision-logic). Likewise the operation of these structures in turn supports the (conscious) waking state.
However it would be incorrect to directly identify the waking state as these various structures.
However in effect this is what Wilber does in relation to his higher spiritual levels. He has not yet for example identified any coherent cognitive structures for these levels (though I would strongly maintain that they are vital for a proper integral interpretation of development).