If it's not cut off it will be marked where the word limit lies so tha tthe marker can see it. Probably better, cos then he/she can see how much over you went.
As for it "just being conclusive material" I always find the conclusion to be more important. You can afford to miss a point from your essay as after all they are not testing knowledge on the LNAT, just an ability to argue. Therefore I would put the conclusion as probably the most important paragraph. Indeed, if I was running out of time in an exam I would always conclude as a priority before I wrote an extra paragraph elsewhere.