Research level 13 Processing unit productivity first. Keep the beacons in the recycler part of the blueprint at normal quality. Upgrading them will worsen throughput without any benefit. You can further recycle and get [item=iron-plate,quality=legendary][item=plastic-bar,quality=legendary] at 25% efficiency and [item=copper-plate,quality=legendary] at 6.25% efficiency. However, preferably use the optional blueprint for [item=copper-plate,quality=legendary] (second to last blueprint in the book).