I have no doubt that the slower parts of Slime builds to something great. It is a well written story and I have enough confidence in the author to pay off the slow portions. I simply moved on at that point (I think I caught up with the current chapter at the time, and I didn’t want to wait for each chapter). I plan on coming back to it at some point once it is finished. I am in the same boat with Danmachi, waiting for it to wrap up before consuming the whole thing.