Wow, epic puzzle

This was a 4r solve until i realized the waste could be made into another pair of products.

i understand how the water-quicksilver pair is not grabbed at max rate but i wouldent think an extra 2 water and 2 quicksilver would be benifical, since if i use the said two quicksilver for metal promotion i wouldent be able to make the product with the quicksilver in it, and if i only use one then i wouldent be able to create 2 bronze atoms, rendering the extra quicksilver / water useless. Which makes me belive that this is min rate :D

if there is a way to go below this, uhhh how ._.