Speedrunner mario has the ability to BLJ without doing down b if you press down then forwards then back decently quickly you perform a BLJ and gain 150 speed per BLJ. This gains speed and lets you still do movement so you can gain speed while dash dancing across the stage the easiest way to do this is to dash dance but swing the stick from forward, down, backwards then you do a BLJ. Also if you hold backwards on the last bit you do a continuous BLJ and you gain around 1750 speed this can be used one after another but is decently hard to do.