Just to be on the safe side, I was chiseling some ice recently, and after discovering that slanted ice which has been chiselled is extremely slippery, had the thought of using it to create traps (such as inescapable bowls, or lava-chutes).
This wouldn’t count as griefing as long as I’m only using it for stationary base defenses, right?
BTW, if you see a base that looks like a nova-helix made of ice and torches on Solus, that’s mine, so beware.
Players can always go back to the sanctum and ‘bump’ the warp back to the world so it should be fine.
Sorry to break it to you. But we praise our helpful sancturn. Use our grapples and learnt to creep. So no inescaple traps on this game. 
I wasn’t implying they would be (totally) inescapable, but the lava-chute would be a pretty much guaranteed kill, sans really quick reflexes for sanctum-warping. It wouldn’t be very hard to make it essentially inescapable via grapple either…