Menahot 8: The Kohen Gadol's Bag-Lunch

On the "griddle-cakes" of the kohen gadol, Rabbi Yohanan addresses how partial cakes can be sanctified. But a beraita makes it clear that they needed to be brought as full cakes, not partial ones, so the kohen gadol could bring the amount of a smaller cake for the morning and afternoon, which might be lesser in some aspect, but no less sanctified. How does all of this connect to the ordinary minhah offering - why not learn one from the other? Plus, when do you bring a "havitin" without oil? Frankincense? With 4 "gufa" inquiries on this daf, referring back to the case on the previous one.