Have been using the TF for quite a while. Love it.
Attempts to configure the hardware to do this did not yield any positive results. In anyone has experienced otherwise would be happy to know about it.
The solution we have is to create a module with toggle buttons specifying the functionality you want and then binding the pad to the button of the module.
As for not being able to turn the layer off you might want to try and restore the settings of default settings using M-Audio's software that is available for OS X.It's called 'Enigma' and you can download it from the link below.