i was just wondering if there were any hints or tips you guys knew of for the interview process other than the usual, keep up with current affairs and learn as much as possible about the RAF's current roles
You've pretty much nailed it, along with being able to explain why you stand out above other prospective candidates.
I started trying to teach myself as much about avionics as possible too and just wondered if you guys - that actually know how it works - think that'll be of any assistance?
No and maybe yes. Assuming you pass the aptitude tests and medical, neither of which relies on your ability to understand the workings of a multifunction radar or a datalink, the crux of OASC is all about demonstrating leadership potential not technical ability. As with the commissioning boards at all 3 services, you can be a genius, but if you lack that certain something, you won't get in.
Unless you have a burning desire to understand everything there is to know about radars, I wouldn't go much beyond knowing the big picture stuff i.e. what sort of radars you might get on a particular aircraft type and what they do - air-air, air-ground, synthetic aperture radar etc.
Where that sort of knowledge will be handy is at interview as it's one of the ways in which you demonstrate your knowledge of the RAF and hence your enthusiasm for joining, and it might just be the crucial extra tick in the box to get you over the line if needed. But that will only be one small part of the interview, don't focus on it. Spend your time gathering your thoughts and putting your evidence together as to why you should get the job and then let the RAF pay you to learn about avionics down the line.