Yes, leaving them on can be a real concern esp in urban situations. My first bike (2013 T100 Bonneville) I fitted with a automatic signal canceler (Kisan SignalMinder) and it has no doubt saved my butt numerous times. Has a settable delay (10-30 sec) and the shut-off is prevented while the brake light is on (so while at a traffic light waiting to turn etc). Thinking to research if positive earth is compatible with it. There is a new option (though at 2x the price) call Safe Turn System (
https://safer-turn.com/product/smart-turn-system/) using accelerometers/motion detectors/gyros to determine when your finished your turn etc.