I am sure I read somewhere many moons ago that a proportion of the lift from an aerofoil was generated by the downthrust it gives to the air as a result of A of A, about 20% rings a bell. For instance if you hold a perfectly flat board horizontally into an airflow & gradualy tilt it towards the vertical it will give give an upward lift. Obviously it is a very crude wing & drag will soon take over.
Taking another example. if you hold the back of a spoon into a flow of water from a tap it will move further into the water flow(coander effect). No water flows on the underside of the spoon so no lift is as a result of the example above.
A wing will produce lift even with a negative A of A ( about -4degrees in the case of a typical light aircraft wing) so surely this must be entirely generated by the wing camber & not downwash.
This may be an over simplification, but that is my understanding.