Being head shy is not a defect in BP's that we should attempt to "cure".
That said I have noticed some BP`s are more head shy than others and the seem to be less so as they attain a size where they don`t feel as threatened by every passing shadow.
One BP I have seems to refuse the `Ball`Python moniker in favour of the Royal Python name. He will not ball up for anything except comfort in his hides. When he is out he is out and if you come at his head too quick you will get bit, with never a thought of hiding his head. Another balls up as soon as I take her out and after a few seconds to a minute pokes her head out and explores once she realises there is no threat.

Let your snake be the animal it is and, develop a sybiotic relationship with it. It may become tame but, it will never become domesticated.