While rereading James’ post he doesn’t actually mention anything like True Creative.
I bolded the bit above that I’m about to reference. I think the easiest limit is to not even start that “if” hypothetical at all. Simply don’t allow free portals and nearly every problem is solved in my mind. That solution allows for all three of his first points to be possible. And again, if people REALLY just want to build in creative they don’t need portals. If they want to open portals they can do so with Oort from survival worlds. If they run out, they can warp to the nearest survival world and go about getting some 