I haven't seen this mentioned anywhere, but with the right position and good timing you can do more than one dash off the same bumper. You have to be right at the edge of the bumper horizontally and be fast with your inputs but it's possible. For example, from the left edge of a bumper 6-dash 3-dash for a little bit more distance, or even 6-dash 4-dash 6-dash to mess with your opponent's timing.