* You cannot instruct from ab initio for PPL unless the trainee has completed their first solo navigation flight after which they can handle the controls as PIC. In which case the student will pretty much be at the end of their course anyway.
I had my first solo XC during my PPL at around 17 hours or so, it was less than twenty anyway so less than half way through the course.
I would be interested to know how that restriction has been established, I don't know whether it is correct or not but given that the OML applies only to a class one medical, and you can instruct for PPL on a class 2, how does it work? You could let your class one lapse and then you don't have an OML so how can it be enforced?