This is not really an isle idea, but cave systems that lead to an islands "core" so to speak could be a thing. In fact, I thought of the fertile isles core cavern. Spawns would be: Raptors, carnos, glowtails, equus, ovis, piranhas, sarcos and Baryonyx, a very rare spawn. Seekers are a little bit too difficult for the fertile cave. Resources would be metal, obsidian, and one node of element ore.

I haven't seen the map yet, but judging from what I've seen on the core maps... we're missing a good look at the Arks' superstructure. Even on Aberration I was disappointed to see that we don't really get a glimpse at the underpinnings of the Arks - I wouldn't mind seeing some good ol' support beam lattices. Perhaps some "deep" place where the ground actually --ends-- and all you get is a set of maintenance platforms suspended over space?

--EDIT--

Well, not "suspended" maybe - attached to the support beams, obviously. I assume the Arks are all automated and run by AIs, but you sometimes need good old manual labour to fix stuff. Robot platforms? Materials delivery ducts? Maybe an odd log terminal or two? Just some thoughts. Buildable, wide-open spaces, with all the bonuses and drawbacks that entails.

https://cdn.shopify.com/s/files/1/0965/1274/products/IMG_1011_large.JPG?v=1506938292 this wouldn't be a bad inspiration. https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcQ-fiPHJgJDK-Q6_82cdI8ax8qOaJPMCZAhZjpMqlVNEzxQ3qNJZA -- this would also help, considering that part of the design (and perhaps some of the restorative attempts?) would be guided by the AIs themselves, and we already know computers --don't-- think like humans do...

This would be cool. Maybe have one island that is completely empty, just a large peice of floating rubble. My idea would be that it looks sort of, odd, and wrong. It is covered with webs of cracks, and these cracks are glowing purple, because they are filled with molten Element. On this large, barren island, there is the enterance to a TEK like cave. When you go down, into it, you get to see some of the maitanance systems of the ARK. Including this one described in this quote from the Helena Aberration Explorer Notes.

"As we made our way deeper into the station, we passed through a massive chamber. It was so vast that I couldn't see the bottom of it from the bridge we were on. Yet it was packed full. From wall to wall, it was filled with specimen tubes, each containing creatures, fetuses or eggs.

I knew from the holograms that I'd seen on the Island's control center that each station created it's own creatures, but I'd never seen where the process actually occurred! There were specimens for every creature that lived on the station - from dinosaurs to huge, alien looking monsters."

And then this second chamber described in this next quote.

"Ever since I saw those strange holograms in the Island's control center, I'd considered this possibility in the back of mind, but I wasn't prepared to confront it. Not directly.

The room was similar to the one with the creatures, if much smaller. Specimen tubes lined the walls in neat rows and columns, but these all held the same species: ♥♥♥♥ sapiens."

Off of this isle at the surface are little portal like machines. A cool asthetic, but probably an impossible one, would be to make it so these portals are the things which spawn creatures into the game, and they glow for a moment and humm whenever a creature or player spawns in. Again, likely impossible, but a cool idea.

maybe a complete water island with no solid objectd at all, just a chunk of water ro some strange liquid.maybe even liquid element

Originally posted by PASTAAAA:

maybe a complete water island with no solid objectd at all, just a chunk of water ro some strange liquid.maybe even liquid element

Maybe a kind of "Bowl" of rock around the water to make it more believeable with a bottom and possibly a water cave within with liquid element at the bottom of the cave like deep sea brine pools?

i think the map does need some water the idea i had was to perhaps have the idea of a lake that got torn into smaller parts with many waterfalls connecting multiple pools

How about make creature mods to go with the map

Originally posted by PASTAAAA:

maybe a complete water island with no solid objectd at all, just a chunk of water ro some strange liquid.maybe even liquid element

yeah like because its in space there could be a floating mass of water or even an island of water

Originally posted by M.R. Smith:

Off of this isle at the surface are little portal like machines. A cool asthetic, but probably an impossible one, would be to make it so these portals are the things which spawn creatures into the game, and they glow for a moment and humm whenever a creature or player spawns in. Again, likely impossible, but a cool idea.

Actually, Genesis does this in the 'space' biome, just randomly on the map and without the pads -- so maybe not as impossible as one might think.