quite legitimately log a large percentage of their student's PPL training exercises as flight time under IFR by flying (amongst other things)
Since a PPL Student is training for a VFR only qualification I cannot see that they should (or could) Log any of their training flights as IFR.
The aircraft either flew IFR or VFR so the Instructor could only legitimately log the same rules as their student.
As mentioned in a previous Thread, I believe the only IFR flying that is permissible in PPL training is that short period to cross IMC (ie climbing above a cloud layer) in order to achieve the best VMC possible for the planned exercise.