After hammering on my keyboard (somewhat) coherently for a long time, I would conjecture that the board is too large. So I tried to us down and either left or r

After hammering on my keyboard (somewhat) coherently for a long time, I would conjecture that the board is too large. So I tried to us down and either left or right alternately and switching left and right when a position would not move anymore. At least until 8192 and ~200k points, random fluctuations seem to clear always enough stones that the board was never more than half full.