How many times have you taken the HF final mock exam? Was thinking of taking it now but I might be able to memorize the questions/answers. Can you share your experience on this.
Frankly speaking, just do the final mock exam once. But make sure you're ready before you do it.
Ask yourself if you don't have the luxury of the final mock exam, will you still take the actual exam? If yes, then you should take the mock, see if you can pass, check out your mistakes, read the specifications/DTD/HFEJB for areas that need reinforcing, and go for the actual
test.
Don't keep doing the mock exam, as you had said it, you might end up memorising the answers hoping that some would come up in the actual. That entirely defeats the purpose of a certification.