The flash is the most irritating when the game pauses to show death notification... with the flash being frozen in the background. The flash itself is fine, but as it is now, it's either weird - why should a tiny explosion lit up the whole map? - or invisible due to the screen being swamped by a huge sea of flame anyway. It doesn't produce actual light either - you might get lucky and spot someone during that split-second, but your soldiers won't.