I think it will be challenging to measure and dispense 4 mg of olive oil as it will be extremely difficult to get out of the measuring container. It might be helpful to know how much a drop of olive oil ways, and how many drops are necessary. If a drop is over, maybe way over, 4 mg, how would one go about measuring and dispensing the thick viscous liquid?
Besides this "How would I do it?" question, this sounds really interesting.