Have u tried more then one 7700k igpu? Maybe you are lucky and yours is decent. I tried 12x 7350ks and the max clock range was massive. Its more you need to bin. Do u think in a memory competition people will all be pushing the mem as hard as possible also so gains from pushing mem because your igp sucks is kind of a non issue imo.
Score wise are you using the same driver that rsan is? Maybe a newer one also scores better. Make sure to compare apples to apples.
I appreciate your passion for igp. Maybe you have found your niche.