It's probably doable. I note that sunflare rockets have a lens flare when fired at the lit sides of objects, like a station or a roid.

Can we have lense flares from the sun please?

I think glare would be a better effect, since it can be used in one's tactics (get the other guy pointing at the sun, so he can't see you very well, then attack). Thereby being more realistic and enhancing game-play.

Besides, you don't really get lens flare unless you're looking through a lens (it's the effect of a bright object's light reflecting and refracting off the many elements of a camera lens). But as a bright object (e.g. a star or sun) comes into view, you would get glare off your cockpit glass (since it's not perfectly smoth, being constantly bombarded with space dust and all), and your pupils would contract (or you would have to somehow dramatically reduce the amount of incoming light to avoid eye-damage by filtering the cockpit glass). This would make it very hard to see when pointed to a bright light source.

Could spawn some interesting and skillful tactics and/or escape methods.