SMW has a peculiar memory layout for controller input (one portion of the buttons is two bytes away from the other in RAM). I've been tinkering with Input Viewer lately and can't it to work correctly for SMW because there seems to be no way to specify individual addresses for the two separate locations to pull the controller input from, it always assumes that the bytes are right next to each other. Therefore A, X, L, R can't be displayed correctly.
It would be a suggestion to the author of Input Viewer to support "scattered" controller input bytes
