Grad school application and sending more than they ask for

Ever? I am sure there is some alignment of the planets where the plus of the 4th letter overcomes the minus of "cannot even follow simple directions". But I can't think of any.

 

Your best bet is to follow as precisely as you can the application procedure.

You don't get bonus points for having a fourth reference.

Most applications will, require you to essentially submit your CV in one form or another. Some will ask for it explicitly. Others will have you fill out a form that contains about 90% of what would typically be on yur CV anyway. So if you're asking whether it's a good idea to put one together at this point, the answer is yes.