The Offhand slot for torches is a really nice quality of life touch, since constantly swapping between the pickaxe and a torch is one of the more tedious parts of games like this. Gating Aetherite behind the boss is a good way to give the fight a reason to exist beyond its own loot drop.
One thing I'd be curious about is how the boss gets summoned, because a hint somewhere in The Overgrowth about what you need usually saves players from having to look it up. With water still being a bit buggy, it might also help to mention the known issues in the patch notes, so people report new problems instead of the same ones. Rain, wind and the improved lighting should do a lot for the mood, both on the surface and underground.
Good luck getting 0.8a out, it sounds like a big step for the game.