Matt
Hi there,
As I am sure you are aware, the requirement for Grad 3 is to follow the guidance in the Rules of Conduct CPD Help sheet which states that less than 20 hours per year is not acceptable so you need to aim for 20 hours or more.
Therefore you need to work back from your document submission date 12 months and in that period develop relevant CPD records.
With regard to your 80 hours you can submit as much as you like and if the 80 hours are all relevant then that is completely fine to submit them all. To define 'relevant' I would always suggest undertaking (wherever possible) CPD relevant to your current employment and the competencies you are declaring.
I hope that helps
Kind regards
Jon