Sent in a ticket about this with no response so I'm going to share a fantastic way to grief others. We all know a foundation has a fairly short decay timer right? Well, if you want to truly be an asshole, you can stick a cheap storage box on top and effectively triple the decay timer on it. Even if the foundation is demolish-able, you can't do it as long as the storage chest is on it. So for 30+ days you can block someone from making any kind of building or expanding their base.
Just sharing this because it needs to be fixed but no one seems to care.