Thinking about it, I should probably only convert your sysex into CC by adding the following code into your gig script editor:
On SysexEvent(sysex: SysexMessage) From Focusrite
Select
sysex == "F0 43 70 78 41 53 01 F7" Do InjectMidiEventViaRigManager(Focusrite , MakeControlChangeMessageEx(20, 127, 1));
sysex == "F0 43 70 78 41 53 02 F7" Do InjectMidiEventViaRigManager(Focusrite , MakeControlChangeMessageEx(21, 127, 1));
sysex == "F0 43 70 78 41 53 03 F7" Do InjectMidiEventViaRigManager(Focusrite , MakeControlChangeMessageEx(22, 127, 1));
sysex == "F0 43 70 78 41 54 01 F7" Do InjectMidiEventViaRigManager(Focusrite , MakeControlChangeMessageEx(23, 127, 1));
End
End
Hence you will be able to MIDI learn the button of your old Yamaha controller to any GP widget. Set your widgets to “momentary to lacthing” in the widget properties, as with a single state SysEx message the only thing you can do is to toggle widgets.
Tell me if it works for you?