You have a couple issues that are preventing the flip grip from scaling with the rest of the block. The first issue is very simple. You do not have the flip parameter included in the scale action's selection set. There is a second issue that is easy to solve but a bit more obscure. A flip action is scaled based on the relationship between the flip action's base point (center grip of flip line) and the base point of the scale action. In your block, your scale action is dependent so it inherits its base point from the base point of the linear parameter with which it is associated. You happen to have the linear parameter base point and the flip action base point stacked on the exact same point. Because of this, even if the flip parameter is added to the scale action selection set, the grip still will not scale with the rest of the block. The solution is simple, though. Move the flip parameter base point to the location of the grip. With those two issues addressed the flip grip scales properly. See screencast.
