Why shouldn’t it benefit their squadron? They have got some extra knowledge and skills that they should be happy to pass on to younger cadets to enhance their cadet experience. If you have a cadet who has completed say Silver DofE you may well get them teaching or helping with map/nav skills, it’s no different. We had a cadet back in 90s who started work as a carpenter and he led several projects, helping cadet learn the skills using materials and tools. He wasn’t an academic by any stretch, but today he has a rather nice house in a nice area and drives a plush Range Rover, funded by his very successful joinery business.
After all, they are being kept on because they have “worth”.
One of the boxes needed to be ticked is first aid, so the cadets can teach it post 18, so by the same token do something else like QAIC or JL, bring that to the cadets on their squadron at least.
The only USP we have is flying training at zero cost. Scouts and army cadets and sea cadets offer similar opportunities for everything else we do.
But this is the mantra from on high and something I am completely anti, hence either stop cadet service at 18 or just allow them to stay on with no expectations, like it was in my day and until 2003. The only difference is that now, there is very little the 18+ can do activity wise given the lack of opportunities means younger cadets are generally targeted.