I followed through on my own advice and now have all the biweekly coin dungeons cleared and S-ranked. The War Dragons are pretty much a joke now that the all attributes restriction applies to sub elements. That’s fitting, though, as they are quite useless.
Speaking of coin dungeons, I wonder when we’ll start to get new dungeons (Star Vault, anyone?). I don’t really keep track of the changes JP has seen, but in addition to getting 2x coin dungeon drop rates, they’ve gotten new alt. dungeons like King of the Gods and some collab dungeons like Gunma. Now that the Bowl Dragons are done, perhaps we’ll see them enter the rotation a la Insect Dragons?