With today's tecnology there really is no need for Poxy voting. We could easily have a secure online quorum to place votes directly by members. If a large enough portion of members truly want to change the voting system they can start revoking their proxy vote permissions. If enough of the membership does this, then voting board would not have enough proxy ballots to reach an official quorum and voting would come to a halt. This would require a pretty large organized effort on behalf of the membership to work.
Just my two cents :-)