Does the efficiency stabilize because we are not going to any pool that is less than 43%? In your simulations can you say how much time the hopper would spend at the PPS pool (or how much time there was spent with no pool being less than 43%)? If the amount of time spent at PPS is a tiny percentage (because of all the available prop pools) then the efficiency would seem to be high but not because you hop away from a pool, but because you are always hopping TO a pool that has low shares.