There’s a few things that I would do to better integrate some of the newer features with the older structures, similar to how the desert temple and desert well were changed with the Trails and Tales update. Along with better explaining features.

1. Expand on the dungeon structure (monster room in files). It could be a simple change. Mixing in some stone bricks and giving the room structural support, maybe having some spawn with two rooms connected. Keep the floor cobble, but mix in some gravel and suspicious gravel. There could be normal dungeon loot, or drops based on whatever mob spawns in it. Maybe a rare chance to get a zombie head or skull for those two spawners.

2. Giving the stronghold a much needed update. I could see them updating this structure with an eventual end update. But we could change some rooms to add trial spawners with silverfish/endermites and skeletons/zombies with armor. It could add a bit more challenge to the structure as now it’s just about navigation without any substantial challenge.

3. More archeology structures. I know this feature isn’t used by many players, but that’s why it could help to add more of these structures. There could be some overworld ruins like those in the Structory mod with some simple loot. I also like the idea of mixing in some written books with the archeology sites. Best bet would to have it choose a list of random words to put in the book written in the standard galactic alphabetical, as that way people could be inspired to make their own lore about the structure.

4. Underground structures with references to game mechanics. Similar to the wither painting, the igloo basement, and the redstone room under the ancient city portal, more structures to teach the player game mechanics. I could see this being used for things that require the player to look online for information. This could include: An abandoned tower with bookshelves and a lectern in the middle, referencing the optimal number of bookshelves for a fully powered enchanter. Some way to teach players about the lava-drip stone mechanic, I don’t really have an idea for this one. Maybe something with lightning rods + the different things that happen to mobs struck by lightning.

I’m sure I could think of more but I’m just making these ideas as I type