Hi @karl_lew,
"There are these four kinds of clinging: clinging to sensual pleasures, clinging to views, clinging to rules and observances, and clinging to a doctrine of self". (Bodhi, MN9)
I agree with you that identification is not really a self. I belief it is like you say
One cannot cling to a self. But one can cling to, for example, knowing to be yourself or to Nibbana as oneself.
I belief MN1 says: if this happens, then sakkaya ditthi is not yet uprooted, because the habit to conceive something like me and mine is still present and taking control again in the mind.
I think MN1 describes how strong the habit is to start to conceive the experienced as me and mine. I belief this is the power of sakkaya ditthi.
Asmi mana is, i belief a different habit. Asmi mana is, i belief (but correct me if i am wrong) about mirroring and it’s structure is: 'there is bodily awareness, so I exist" and vice versa. “There are thoughts, so I exist” and vice versa. 'There are emotions, so i exist" and vice versta. It is like a mental mirroring. If you look in a mirror and you see the reflection of the body your mind becomes peaceful because it acknowledges “i exist”. If you would not see your body, you would become very anxious.
The same is happening inside. Many people are always emotional because that is when they feel the most “i exist”. Their emotions ackknowledge ‘i exist’. So they keep it alive. Many people do not like dipassion because they get the feeling they do not exist anymore in dispassion. etc.
I think it is a very deep habit to perceive it this way that there is inside us a knower. Maha Boowa, in my opinion, describes that fundamental avijja causes this perception of a knower-who-knows. The mind is almost all the time loaden with this perception. It is like avijja prevents us to see and discover this duality is not really the nature of our mind. At least that is how i tend to understand his teachings.
We are so used to this inner perception of a knower-who-knows that we belief this is how mind is, it’s nature, while he says, this is not at all the nature of mind, but still a defiled state of mind. Avijja is like a lens which creates this vivid notion of a subject-who-knows-an-object.
Maha Boowa describes (in arahattamagga/phala) how, for him, suddenly avijja totally disappeared from mind and thereby also it’s effect on the mind. At that moment he clearly saw a knowing nature, the (pure) citta.
He described it as unborn. I do not know.
I think it is not bad or controversial to speak about true self as the original or pure state of mind, Nibbana. A state freed from adventitious defilements such as asmi mana and avijja which delude the mind in a very strong way and does hinder us to see the original state of mind without defilements.