Suppression effect lasts way too long from bullets. Seems like effects from mortars/explosives last for a shorter time which should be same for bullets.
The overall effect on your screen making everything gray and blured is awful.
Dubs made this which would be far better and easier on the eyes, explosives and large caliber guns can apply the heavy suppression effect where everything is blured while small arms apply this vinette effect.
And instead of twitching there should be slight misalingment. So instead of not being able to see the target due to blur you can actually return fire with slight inacuracy to your shots.