As before, avidya/ignorance means also the mind in the beginning of a kalpa, when the categories of samsara and nirvana have not yet appeared. This is evident in the Aggañña sutta, as an example. The first beings are ignorant in the sense of not-knowing at all what it is that appears, they are amazed and curious at it, they experience a sense of wonderment. Avidya is also a not-knowing in a pure or neutral sense, it is like innocence, without moral judgements.
The negative judgementally coloured avidya is not really true, it is not the whole truth. Avidya/ignorance is empty of true existence, like the whole samsara is empty of true findable existence. Ignorance is primordial purity.
This doesn't mean that avidya is a form of consciousness (going back to the point we were discussing).
You probably haven't thought about it carefully, when You say that a mental state (avidya) is not a form of consciouseness! This equals saying that it is not a mental state !!
Do you envision avidya kind of floating around in empty space ??
There are different forms of being, other than the human body and mind. We are only very much identified with our bodies and minds, and therefore we can't imagine or experience other kinds of existence. Like the Arupyadhatu, as an example.
In Abhidharma kosha
Vasubandhu describes different forms of being in terms of 22 faculties (indriya). Other forms of being have less faculties, like the beings in Rupadhatu and Arupyadhatu, but they all arise as is described by the 12 Nidanas. When one is born as a human, at conception one has only two faculties, the faculty of vitality and the mental faculty of indifference, the other faculties develop gradually thereafter, (says Abhidharma kosha).
In his explantion of the 12 Nidanas Vasubandhu says that the 3. link, Vijñana, is the period from conception to the point of actual birth, and 4. link, Namarupa, is existence from birth to disintegration.
This supports the view that third link is Alaya-vijñana, and that Manas and sense consciousnesses develop in the links following after it.