Actually, talking about precommitting is any case a side issue, because it happens before the start of the game. We can just assume you've never thought it before Omega comes up to you, says that it has predicted your decision, and tells you the rules. Now what do you do?

In this case the situation is clearly the same as the lesion, and the lines of causality are the same: both your present disposition, and the million in the box, have a common cause, namely your previous disposition, but you can do nothing about it.

If you should one-box here, then you should not smoke in the lesion case.