It's not just secondary duties though is it, it's how they perform in them. Can they back up evidence that they had a managerial, leadership role and/or have responsibility in that position and have exercised it effectively. Also, I'd definitely recommend continual recording of what you have been upto. Last year and this year, I collated upto 6pages of A4, neatly typed up, for my 1st RO to disseminate into my sjar. I wrote them in a statement and fact style, I.e. backed up why I've shown this because etc. It's wasn't all other non trade work stuff either, although I've been in a premium position at my place to be able to be 'supervisor' for lots and lots of jobs so have written about them. But not just written 'I have been able to supervise a csas bite', I expanded each bit. I've done a Junior leadership & development course (JLDC) which I got good insight from and was defo worth doing (almost becoming mandatory for SACs to do now). And I've organised visits, done airshows. I also have contact with industry, and am In charge of all software, maps crypto, etc, organise configs for dets, etc. Just give your 1st RO, the best evidence you can so it's easy for him to write it.
I've seen guys just give ROs a quick drawn up scribbled list of their 'achievements', then moan a year later when their still to being read.
So I don't think it's what you've done, it's how your doing it. Play the game, not just tag along for the ride then whinge when it doesn't happen.