A controller add-on includes a housing that mechanically couples to a game controller body. A conformable surface of the housing is configured to conform with a bottom of the body of the game controller. A plurality of buttons coupled to the housing are located opposite the conformable surface. A controller interface coupled to the housing is configured to communicatively couple to the plurality of buttons to the game controller. Buttons on the add-on may be mapped to controller buttons using customized button mapping pre-sets. A button mapping may indicate that a selected preset is to be hidden during a switching operation Upon receiving a switching operation input, the selected pre-set is skipped during the switching operation.