If they the insurance company want to be dicks about it. Lets say your vehicle is lowered and you never told them about it. God forbid you get into a collision and you make a claim. Surely at that time when the vehicle is being viewed, they can check if the suspension was modified. They're always looking for ways to cancel a policy or not to pay out.
That's something I wouldn't want to test them on. Especially if vehicle(s) were a write off or if you or the other party was injured. And your left with no coverage.