The problem lies in the framing of the question.
A character defect is either a mental attitude / belief or the action flowing therefrom.
All mental attitudes / beliefs and therefore all actions are available in principle to all people at all times.
They do not belong to us; they are not what we are; they are paths down which we may travel in time.
Someone with many character defects is not someone who possesses them (or is characterised by them) as one would be characterised, say, by having brown hair or liver spots. He is merely someone who habitually resorts to particular thoughts or actions in preference over other ones.
Freedom from character defects would therefore be the ability through God's help to go down different paths of thought or action.
That the choices made will never be perfect is obvious.
However, if, in any moment, one is not angry, one has been perfectly relieved of that anger, in the same way that, if I am not walking down Main Street but am walking down Hyacinth Avenue, am I entirely and wholly walking down Hyacinth Avenue.
Part of the problem with defects is precisely the identification with them and the belief that we are stuck with them because that is who we are.
If we are identified with Main Street, we will always feel uncomfortable with Hyacinth Avenue and always yearn for Main Street because that is where we believe we belong, whatever suffering Main Street may bring.
It is exactly the same with, say, anger and equanimity.
We are so identified with anger that equanimity feels fraudulent and alien.
Perfection can be attained moment by moment: I can be perfectly free of anger for a moment. Or more.