I agree it might be polite for pre registrations to announce themselves to the Supervisor. But why should they. They have paid their money it is their seat until the comp starts. They have pre registered for a reason, usually expecting it to sell out or knowing that they may be too late to register but be there for the start.
Any supervisor worth their money, should be able to sit several reserves and still start their competition on time.
Yogi
There speaks a top Supervisor. We miss you Yogi.
I guess it would be politically incorrect to ask you what you'd have done with Mr Mallu's chips had you still been there......So I'll wait till I see you next & then ask you! A fascinating & very awkward problem.