Slice your own Kalamata or green olives in brine, the flavor improvement is noticeable. Anchovies might be good for the same, but if you’re going for a protein, why not go true Hawaiian style (not from Hawaii I’m pretty certain) and use Canadian bacon?
I hate pineapple and tomato sauce together so no to piña pizza but anchovies, kalamata olives, and crushed red pepper is delicious. Onion too if you are looking to add the sweet element, but it doesn't need it.
I do like other versions of cooked pineapple (pineapple and shrimp skewers marinated in chili paste are transcendently delicious, and pineapple upside down cake is good) but not with tomato sauce and cheese NO.