However, a new filter to rocket silos (similar to filter inserters) could signal to the game we also want to fill the rocket with blue circuits for example, if that filter was set. There could be an option to set the filter via the circuit network, for mixed rockets, or reuse the same rocket ...

Yeah I feel the lack of an option to circuit control harvest separately is an oversight in Glebas game design. The whole point is to keep things as fresh as possible, so not being able to properly control the planting and harvesting, just makes me more annoyed with the spoilage system, which I don't ...