The Underspire is a large mostly bland dungeon. Can you add some treasure rooms for more variety and rewards? By treasure rooms I mean the mini-game that is found under the games tab and requires a treasure map to play. Unlike the standard mini- game it should offer currency rewards depending on how many turns or the number of high end treasure chests you open.
Rewards would be underworld shards, diamonds, Dragonite, cursed gems, torches, laterns, gem shards, gnome song verses, etc.
You could even make it that the more maps you spend per run multiplies your earned rewards. You can allow VIP players to spend more maps than everyone else.
Daemon/Genie would be a much more interesting choice in the Underspire than it could ever be in Daily Delves or the all-too-brief Explore mode. Especially if you received a significant bonus/penalty early on that would persist through the rest of the week.