From a powerlevel/ability analysing standpoint Egghead might turn out to be one of the most interesting arcs.
If Kizaru really gets there and it comes to a fight, we could learn if FS is really required in order to keep track of him and the Paw fruit sucessfully, cause both happen to have atleast top5 movement speed. And if the Seraphims turn against the SHs, we would also get to know their durability threshold and by extension perhaps King's.
And Oda would just have dropped/confirmed two types of awakenings in one arc, which is crazy knowing his writing style.
But I don't know if it's really happening. I mean can they really go all out on Egghead? They are still evacuating and with Kizaru's track record, Lab Phase and anything else won't last long. A fight against Kizaru would devastate the whole island.
Good thing would be, that Kizaru being there would mean that Sentomaru and the Seraphims might go against the SHs.