If you can't go sub-500ft without getting grief one really does wonder how effectively you can teach PFLs. Back in the day when I did my PPL we used to take it down to around 10ft. Whilst a real engine out is very different (way more draggy with a windmilling prop) when it did happen it was almost a non-issue.
Sometime later when I did my instructor rating the school commented that the question had been asked of the CAA how many instructors had been prosecuted as a result of low flying complaints as a result of PFLs, as no matter how far in the sticks you think you are people seem to have a habit of strolling out of the woods with their dog/horse as you come over the fence. Anyway... the answer was zero.