You should ask your instructor how well he knows your examiner's habits - for example, are there questions he always asks and has he any favourite nav routes?
My instructor got my route for me from my examiner the night before the test and said that, from other students' experiences, the diversion would probably be at point x - and it was!
On the day, once the examiner was reasonably satisfied that I was safe, the test became a very pleasant chat for the remainder of the 2 hours.
And that was with a totally messed up pfl, which he made me do again immediately (ok 2nd time).
Time spent on reconnaisance is seldom wasted!