I think you are over thinking this.
First focus on passing d test and forget about after. The test is easy enough when you do a few lessons.
After you pass your test and you still think you not happy with the reversing nothing stopping you on going back and doing another few lessons but this time you will b able to tell d instructor what you want to do as he wont b thinking of getting you past the Test.
First artic job i did was about two years after passing the test. Went and did 3 lessons and did a bit of motorway driving,reversing etc.just to settle myself before starting the job.