I'd imagine having a strict boundary between "software thing that calculates how much you need" and "robot thing that mixes stuff together" would help, and you'

I'd imagine having a strict boundary between "software thing that calculates how much you need" and "robot thing that mixes stuff together" would help, and you'd set up guardrails and unit tests on the calculation part. Worst case you could have physical guardrails such as "can't take more than x mg per week" in the form of only supplying a certain amount of raw materials and topping off intermittently. If you run out you find out sooner instead of a month later.