I want to use my controller to mute tracks

Simple enough.

Akai MPK 88

I have "taught" LPX to respond to Volume and Pan moves for each of the 8 Faders and Knobs.

I'd like each of the 8 buttons to do Mute in the same way.

Can it not do this?

The MPK is sending 0 to 127 values as the button is pushed/pushed again.

But clicking a mute button on a track in learn mode does nothing - so am I to assume it can't be controlled externally?