MLDT Coin-Up Challenge

The Coin-Up Challenge is a mini-game in Mario & Luigi: Dream Team in the beginning of the game, right before entering Pi'illo Castle. The goal of the mini-game is to hit the blocks with Mario and Luigi in an alternating pattern, each time hitting the blocks you go higher. You have to reach as high as you can in order to multiply your coins by a set amount (this is always 50 times X, X being the reward). If you reach the top, you receive a 1-UP Deluxe.

Easy approach
The easiest is to simply alternate between A and B and having an equal amount of time between each attempt.

You want to press the buttons A, small pause, B, pause, A, pause, B, pause, A, pause, B, pause, ... in succession. Every comma indicates a bit of time between the jumps. https://youtu.be/a67G98RURDI

Harder approach
The harder approach is to start jumping with Luigi and immediately after jump with Mario. Luigi's hitbox is bigger, so you move up earlier. Thanks to Luigi's bigger hitbox, you can start jumping with Mario sooner.

You want to press the buttons B>A, small pause, B>A, pause, B>A, pause, ... in succession. Every comma indicates a bit of time between the jumps. https://youtu.be/5UyrgfEC8AI

The best known time achieved using emulator tools on Citra is 16.23, however no video exists of this. Discord message with the TAS info (server invite).

Best known times
The only times I know of are those of myself (Snodeca), and my fastest time was a 15.23 set back in May 2020. I do not know if a video of that survived, however. Proper information will be added once more research is done.