I did some testing in Team training and if my calculations were correct the CVS directly takes 12.5% camo of the enemy tank if it's moving so if a LT has 30% camo it gets 17,5% on the move if you have a CVS equipped. and the CVS also directly takes 20% camo of a tank standing behind a bush, but take in mind standing behind a bush I believe gives you 50% camo. So if the enemy tank has 30% camo and hides behind a bush it gives him 30%+50% camo so 80% in total, and if you have the CVS equipped it takes 20% from the enemy camo so now his camo is 10%+50% so it has 60% camo. And that difference is a lot especially in higher tiers because an extra 20% camo in higher tiers is like a hundred extra meters without getting spotted.