Congrats on the previous KS campaign and best of luck with the next one.
Unfortunately, there's one problem with the store: you don't know which components are available as assets or those from the predefined maps, e.g. I've just purchased underground and only after purchasing can you see Bandit's Grotto has components which aren't available as assets (the bridge, mushrooms, doors, etc.).
It's great you offer pre-constructed maps though I'd ask any assets used for their generation should be made available within the assets or, at the very least, identify which are part of the map only and unavailable separately.
For the price the content is still well worth the money so I begrudge mentioning it though it should be clear what is and isn't available as assets.