I also confirmed that feet can come form large box, but also in the large box will possible to have <Keyitem> + <Max light Temp item > + <Material Item> + <Temp Item> + <Agrument item> + <Feets> while small box you will may got <Material Item> + <Temp Item> + <Agrument item> + <Feets> so form possibility and form my farming exp, i got feet form small box more than large one.
And ya if you hope on some feet, it's will end up you got many of others than get what you really want, I use more than 4-5 run on famming my BLU Feets one run take 3hr+ > 6hrs up to how long i can endure til i get it and then i try get my DRG feet one on same map i get it on 3 run and on the first run i get 2 un-need 4 BLU feet keep comming out ~.~.