Wiggler Hyperspeed
Wiggler Hyperspeed is a hyperspeed method where Mario builds up speed by repeatedly bouncing on Wiggler. By manipulating Wiggler to the sides of the boss fight arena, the ceiling can be low enough for Mario to bounce on Wiggler and be pushed down by the ceiling every frame. This causes Mario to build up speed.[1]
Applications
It was theorised that with enough speed, it would be possible to clip under the ground, and collect Wiggler's Red Coins in 0x A presses, however, Mario would also need enough speed to clip through the floor, and his terminal velocity is only -75, so he would not be able to clip under the floor. Furthermore, Mario gains FORWARDS speed from Wiggler, so if you could jump after gaining speed you would jump extra high instead of extra down. Even then, the star would still be 1x A presses and we would still need to figure out how to solve the remaining A press.