Yes. I believe so. Though its only buildings from what i've heard.
IS "colonizing" cave locations possible? Will it prevent raids/have downsides?
Colonies in caves seem to be inactive when you are not inside that cave. So if you put a mine in the cave and go adventuring, you'll return to notice that there is almost no work done in the mine.
Also, rocks in caves respawn, and it looks stupid when you come back to see a rock in the middle of your buildings.
Overall, I don't recommend it.
I built my first base in my first playthrough in the "South Mine" right next to the entrance that is next to the woman only village. I had a male only guard camp at the entrance of the cave outside to deal with raids, and as a storage area for loot / bodies.
It is definitely very feasible and will prevent raids if you have a person with a decoy amulet inside the cave.
Note that you can't put your blue base flag inside a cave even with the block building option disable in the debug settings, so if you want to keep your other main character protected from random patrols or respawning animals, you would have to do the /change exploit to manually move them inside and then quickly swap to your other main character to set their location otherwise they will try to walk out.
I wasn't aware that they stopped working when I was in the mine since whenever I went to harvest boxes and other work buildings there was always a ton of stuff. But the again I spent a lot of time in the mine so I might of not realized that I should of had more stuff when I was adventuring outside of the cave. But from what I could see when I had all the names turned on the villagers were still moving around in the cave even though I was outside it.
The only annoying thing was the bats and the Angler (Purple Ore) monster constantly respawning every time you went in and out of the cave. And I went in and out a lot cause I was moving captured natives and loot from the entrance of the cave into the cave. Especially at night time when I would do night time surprise sex kidnapping raids on the Women Only Village, and Loli Village.
So every few seconds all my villagers were running around killing bats, and a lot of them would get knocked out by the Angler that was nearby.
I eventually just spawn trapped the Anglers with 3-4 huts, and put traps to kill them. But I have a bit of OCD / hoarder syndrome where I have to go collect every bit of loot whether I need it or not. So the cave was driving me nuts cause I would just constantly waste time running around my entire village collecting all the bones and purple ore every time I entered the cave. Which is why I went on an a pretty extensive hunt for an area outside that was isolated without any hostile enemies to build a base.
You also had to build a ton of torches otherwise you line of sight would be obscured by the gray darkness fog.
I tended to ignore the rocks and built around them because they respawn, and just left them as decorations. Though they do occassionally cause path finding issues, so not exactly optimal.
Another annoying this is when you built houses inside the cave, and then you build houses outside like at the entrance on top of the mountain, the internal area of the houses would overlap since all internal house cells share the same dimension and only seems to factor in x, y plane coordinates and not z plane (3d height) coordinates. Which then made NPCs get trapped or disappear. Because their AI would detect a door from another house as the closest door and they would keep trying to walk to that one instead of the door of the house that they are actually in.