Whilst I agree that students should be instructed on the use of GPS (and I use it myself in the right seat when students are navigating properly to allow myself more capacity to monitor and teach them), I do not allow my students to use it on any PPL & CPL exercises.
Im a firm believer in the navigation techniques of old. You never know when that GPS is going to fail, and if you do not have a very solid grounding in the fundamentals, you're going to struggle. Most students unless they do alot of excess training simply dont grasp the fundamentals sufficiently early enough to allow extra training in regards to things like GPS.
my opinion only.