I did Potato herbicides post Paraquat. I was fortunate in that I was working for a big spud grower at the time who was happy to use a variety of herbicide programs and see which was the most effective.
I think you have to have a variable that YOU can control like nozzles or herbicides or fungicides. It helps if you can get friendly with a few local growers so you can have a broad spectrum of results perhaps as well.
Where are you doing your course? I did mine at Harper and they were very helpful but I know from others experiences that some of the course tutors can be quite inexperienced at teaching the course and, as you say, quite vague.
"Dogs look up to us, cats look down on us, but pigs treat us as equals." (Sir Winston Churchill)