One of the first competencies we mark you on in the interview is motivation. You need to show a defined interest. The CCF or ACO is exactly the sort of thing we look to see. We would then like to know how far you got. What rank did you achieve, did you complete the BTEC? Did you apply for a gliding scholarship etc.
You experiences on wing training weekends, camps et al will be extremely useful for answering the trickier questions in our competency framework.
We often find those who are younger, yet have done well through the CCF/ACO DofE, to have better life experience and maturity than some of the older candidates.
I dont know about the FPP competency markers, but one of their previous off shoots used a framework marker system that we inherited and still use, albeit adapted for our needs. As a CI in my spare time at my local Air Cadet SQN, i can tell you that if motivation leadership/team work are still in the framework, you can generate some great examples through your time in the organisation.