Thank you for playing!
Yes, a lot of people seem to have a hard time wrapping their heards around the swap mappings.
I'm working on an update that offers input rebinding so players can map the characters to their most preferred button.
Right now the mapping is based on their direction. Vertical formation in the Up button, Horizontal in the right and Cross on the left. The Circle formation is gonna be removed and changed for another formation, which is horizontal but in the Z axis (forwards to backwards), and Candy will only attack on the X axis in return. This is because the circle pattern proved to be very situational and people didn't expect that horizontal could go both ways. Mapping Z axis to down will also make more sense I think.
About the dash/brake. You're right, the current mapping is made to test if it'd work on a single joycon, I'll change that.
Hopefully I can drop this update this weekend.