Saying the Clutch Switch was present but not engaging...
it would send the signal to Ignition Relay and stop the engine in the same way as when starting with the kickstand down and clutch in but it would shut off when putting it in gear.
The Bank Angle Sensor, Clutch Switch, Neutral Switch and Kickstand Switch each of these Fail Safes could be the culprit as they all meet at and are tied together to the Ignition Relay and for just such purposes.
All I can say is to try it and see.
