Unity 5 cloth collision for goal net

I'm trying to use the new cloth physics to create a goal net that is not only attached to moving goal posts (weird I know, but integral to the concept), but also moves realistically on impact and deflects instantiated balls that are thrown at it. I am able to instantiate projectiles that have a rigid body component and a sphere collider, but currently my projectiles just pass right through the cloth no matter how I set up the cloth.

First, I can't figure out how to specify the instantiated objects in the cloth's sphere collider array because they don't exist yet. But from what I understand from the Physics 5.0 upgrade guide, "you can no longer attach cloth to colliders or have cloth apply forces to rigidbodies in the scene" so it sounds like I am out of luck anyway.

I've been looking for solutions that others might have used for character clothing such as a cape, because it seems as if the same concepts might apply, as the cloth would be attached to an animated skinned mesh and you would want it to react realistically to the environment (not pass through objects), but to no avail. Is there a way to make this work?