Without wishing to encourage a walt I'll preface my comments with the following:
Passing POC, AIB and RM Young Officer's Course is hard enough without gobbing off about any SQ, let alone SC. You will have been in the Corps about 3/4 years before being allowed anywhere near JSFSC, so worry about that bit first.
Secondly, basing your choice on Office/Other Rank solely on the length of time you may or may not spend working with the SB is frankly f*cking barking, and shows a lot of immaturity - you become an Officer to Lead and Command a body of the finest men and women this country has to offer; not to dress up in black and grow unfeasibly large moustaches.
Now, back to your question, regardless of your SQ, you can expect to 5 -6 years in SQ post 1st Troop Command and pre-ICSC(L). This is the same for ML, S, SC, etc etc. Post ICSC(L) you can expect to spend sometime out of SQ to allow you to broaden and become competitive for promotion. Once you reach the level of Lt Col, your SQ becomes meaningless, as you will be judged on competentcies, such as Operations, Support to Operations, Planning, etc etc. At this point, being an SC rate offers no more advantage to you than being a Signaller.
If this doesn't answer your question, then frankly tough. Get back into yuor box, start reading your Economist and practising press-ups, that'll be enough for you to think about taking your POC.....
Trying to remember the book my son borrowed about"THE FROG SQUAD" may have been called "FIRST INTO ACTION" I will find out and keep you posted. Good reading I bought it when I ventured to NZ helped to pass a few hours of flying.