Question Can I use a BOSS GT-3 as footcontroller for my G-Major

The Boss GT-3 pedal sends out a controller message both when the buttons are pressed AND released. As the G-Major uses the same CC messages for ON/OFF switching of an effects block, this makes the G-Major switch back when you release the button. Unfortunately, there's nothing to do about that. We recommend that you get another MIDI board that does not use momentary switch buttons like the one´s we recommend to be used with the G-Major or G-Force.