An AAVA ban could be legitimate industrial action .. as long as we are balloted first, as per the policy you highlight
Unfortunately I don't see the current BEC going down that road. They have stated that the Branch Handbook is full of anomalies and the policy you quote is contradicted by their belief that a policy of the union looking after the interests of its members overrides anything. Therefore, in the interests of their members, they state they are going along with management and recommending the 'proposal' instead of calling for a ballot, which many of us would have seen as a more legitimate form of action.
Ho hum.