The PFL that you have to demonstrate during your test should be over open countryside, as field choice and planning a circuit to the field are key. Therefore your practice for your test should simulate these conditions as far as possible. There certainly is value in a 'PFL from the overhead', we routinely do these on the way back from another training detail, but I would say you need field choice and circuit planning at this stage.
There will be a chorus here from folk saying that the best person to discuss this with is your instructor, but it seems that you've maybe lost a bit of faith in them after your experience. Time to ask for another instructor even though it might set you back a few flights.
None of us are perfect and if I feel I've given a student less than good advice, I hope I'd tell them so and discuss where I went wrong and try to make things right next time. I must confess that has happened to me and I hope the student took it in good part. We're all still learning, instructor and student. My first CFI had over 10,000 hrs instructional. When I started instructing, I asked him how long it took before he was on top of it all. He said 'I'm still learning, every flight'. And so it is...
As a general rule, flap should only be used once you are assured of touching down mid-field flapless, then use flap to bring the touch point closer to the beginning of your planned landing area. Full flap should only be used once your landing is assured and you have complete confidence you won't land short.
Retracting flap once extended is a big no-no, so only extend them once you really feel you need them.
It's better to hit the far hedge doing 20 than the near hedge doing 70!
TOO