Balancer option

I would like to adjust the priority of a balancer based on the level of a connected input storage.
e.g. I have a storage for corn leading to ethanol production. When this storage gets over 50%, I would like the excess to be sent to animal feed production. If storage is less than 50%, I would like the route to animal feed production to be blocked.

the feature must be set to Storage, not to balancer, because balancer can branch into multiple branches.
ex)
Storage Input Option
by Conveyor 50%, by Truck: 100%