There are few
scooties and bikes have alarm if you do not turn off the side stand (Bajaj Pulsur 220 have it). <a href="https://www.allindianpatents.com/patents/220469" target="_blank" rel="nofollow noopener noreferrer">Indian Patents. 220469:MOTOR CYCLE SIDE STAND ALARM FOR TWO WHEELERS</a>
I think this is only for noobs and too stressed people otherwise Its basic instinct for bikers to first turn off the stand before sitting on the bike properly.
An Indicator is enough if anyone wants. But certainly you should not be prohibiting user to do something in any design unless it's doomsday. In my suggestion long side stand would be good to notice and it will strike your feet before you put it on gear.
Excuse me but here is the <a href="https://www.google.co.in/search?q=bike+side+stand+indicator&oq=bike+with+side+stand&aqs=chrome.3.69i57j0l5.7703j0j7&sourceid=chrome&espv=210&es_sm=93&ie=UTF-8" target="_blank" rel="nofollow noopener noreferrer">bike side stand indicator - Google Search</a> .
Edit: One more thing on bikes (Not scooty), they are now designing such a way that you have turn off the side stand before you open the left leg base.
Following is also a good option.
Scooty riders sucks, they don't even know what is high beam and low beam in headlights. that side stand indicator should be enough for them.