If you in-place upgrade the Science Block, the Red Science section gets starved by making Green Circuits. With a few output priority changes that can be fixed (see screenshot). Even without the upgrades, I still think that should be the priority in the early game since the thesis of this block is to make science first and the overflow goes to the network.
My ordering of priority for the copper plates was Red / Yellow Science > Red Circuits > Green Circuits > Train Overflow

If you in-place upgrade the Science Block, the Red Science section gets starved by making Green Circuits. With a few output priority changes that can be fixed (see screenshot). Even without the upgrades, I still think that should be the priority in the early game since the thesis of this block is to make science first and the overflow goes to the network.
My ordering of priority for the copper plates was Red / Yellow Science > Red Circuits > Green Circuits > Train Overflow