they are metal so u could bend just got to make sure u bend them all the same so it is still balanced or u can shorten bearings life in fanid fix the angle on the blades if you could so there isnt as much air being moved.
and u want some air movement but downward to clear leaves
im trying to remember if ac blows down on coil or up drawing heat out been so long since i was a ac installer if it draws up u just flip thing upside down or u will just sprayed in the face with leaves and have quite a mess to clean up