I've tried all 3 settings and also keyed in stuff like 64000/128000 just to test and all prints come out the same...like I'd guess 60% darkness, with random lighter/darker rows based on how much black is on that row.
Using 'Fun Print' (com.fun.mxw app name...currently 5.04.22), and its level set to 100%, the same prints are jet black and solid, with no fluctuations.