I would say that the when your pushing the pedal from the top of the stroke theres more force going through the cranks. Think thats what the original posters getting at.
A simmilar thing to taking off chain rings and putting them back on one hole further round, or on the other way round. To stop wear happening on just one area. Of course you cant really do that these days with ramped teeth chain rings.
As for flipping the axle so that the lefts sides now the right side. I have done this on cup and cone BBs. Theres some cartridge BBs that have seperate cups. So presumably they can be flipped over. But they ones Ive seen were really low grade things.