But those outcomes which have a limited initial effect yet have a very large overall effect are very sparsely distributed among all possible outcomes with a limited initial effect.
I still do not see why the pump would magnify the chance of those outcomes terribly. The space of possible actions which have a very large negative utility grows by a huge amount, but so does the space of actions which have trivial consequences beside doing what you want.
But those outcomes which have a limited initial effect yet have a very large overall effect are very sparsely distributed among all possible outcomes with a limited initial effect.
I still do not see why the pump would magnify the chance of those outcomes terribly. The space of possible actions which have a very large negative utility grows by a huge amount, but so does the space of actions which have trivial consequences beside doing what you want.