Whether or not you'd need to use push-pull on the test is totally dependent on what the examiner thinks. If they're a progressive type who values subtlety and nuance, he or she may think that there are many ways to demonstrate control of a vehicle, and use judgement to determine if the way you're using meets the standard. I would estimate the chances that a) such a person exists, and b) you'll get him or her for your test are approximately 1 in 30 bajillion.
What is more likely to happen is you will get is a certain variety of English man in his late 40s to early 60s who believes the push-pull method was determined by the government in 1951 to be the sole correct way to demonstrate control of a vehicle, and has not been satisfactorily shown to be deficient in any way by anyone in the ensuing 60 years.
I'm joking, of course, but my advice is don't think of this as learning to drive; think of it as learning to pass the driving test. You need to drive the way they want you to drive just once to pass the test, and then you can go back to driving like people normally drive.
Good luck!