Caves are coming together with Mutation breeding. Most tribes have alot of 0/0 mutation females in the caves, where they are safe, and not getting sniped.
If you wanna change caves, you need to change breeding aswell. Just do like a DNA/Breeding-Table, where you can insert a Cryopod and it lets you get mutations or something like that.. Sounds kinda stupid compared to how much effort it is to breed all those females each day to push mutations.. but, I dont see an other solution than transfering all this mutation breeding into a structures/cryo-table what does the same. Plus, I'm pretty sure that all those 0/0 females causes the most lagg on our servers.
And when you have fixed the Breeding System, then you can change the caves to whatever you want.. Prevent Structures/Turrets/Change Entrances etc. But right now, we need the caves mainly for breeding.
Another solution.. Disable Vaults/Storage/Cryofridges in Caves.. So people are forced to build outside bases? idk..doesnt really fix the issue