Show me a regulation that states this!
Quite.
....... an applicant who has commenced a LAPL course must complete this course and Skill Test before commencing the course for the PPL
EASA too often was influenced by a bunch of control freaks. Other than with a few exceptions the LAPL exercises and numbers are identical to the PPL. The order that the PPL exercises are conducted is not prescribed and it will be normal for an instructor to adapt to the student and of course the suitability of the weather on the day. There is no way by reference to a student log book or indeed the training record that you can identify between a LAPL or a PPL course save the completed content and compliance.