Think of the classic case of the deadline and what it actually means. Case A, you didn't procrastinate. You took plenty of time to think on the problem, work on a solution at an unhurried pace, put it aside, come back to it, and solve it before it is due. And then, it is done.
Case B, you did procrastinate. You have no time at all to think all day, you immediately do and iterate. Four hours later you've sprinted and delivered. And then, it is done, same as it would have been if you didn't procrastinate, maybe 10 fold reduction in time.
And that is worst case examples. Typical case is probably somewhere between these A and B, but the point is non linear time to output.