Yes, it has happened before with baked potatoes. Yes, 64x64.
I left it purging for 48 hours and there was still enough Iron to crash the server when I destroyed the Sorting Machine. The only reason I managed to fix it was because how the server acted when it was restarted. I would submit a bug report if there was anything useful say but I would have attempted to get in contact with Eloram first because in both incidents the tremendous backlog was inside RP2 blocks.