What's their being a PPL student got to do with it? As was indicated earlier, elsewhere in the world QNH is used by everyone.
At least everyone's on a common setting, including transiting a/c. Even if one or the other is using a 'local' QNH & others an 'area' or 'regional' QNH the difference is minor. I know of no chart in common use that gives terrain w.r.t. QFE so what do you use during departure or arrival? What about mixing IFR & VFR traffic etc?