A useless UI effect and there's no reason why robots would need 'em - but.. Radar tower or some scouting unit being able to launch/fire a ground targeted weapon that drops glow sticks - illuminating an area & removing the fow for a short period of time.
Flares would make sense. Help with scouting things out and not showing exactly where you are or what you are using to scout.
It would be incredibly strenuous on the GPU, but it would be pretty neat of recon units launched aerial flares that lit up an area equivalent to their line of sight every once and a while.
You can mitigate the over-use of units doing this through some mechanics. Remember in Iron Man 2 when the hostile AA bots had those foot-plates that fastened themselves to the ground before launching their AA shells?
