I think the boundary is broken. I made a 192 x 192 square. Then I went to the center, (I checked at least 4 times, and I am 100% sure that it's the center) than typed /setBoundaryCenter. But I didn't know how each unit was measured for the warn/kill radius. So I fiddled with it and got 46 for the very edge. But then I went to the other side of the square and it let me go much further than the other side I was on before it gave me a warning message. And it was set to box too. Same goes for circle.
deathwishez is cool.