The role of Op Allowance is to compensate the people getting shot at in Operational theatres, FI does not fall into that category. As for doing ones job and spending time away from home, you are entitled to LSA whislt serving in the FI, thats there to compesate for time away.
A general observation I have on the whole thing. Isn't "getting shot at" also "doing one's job" ? Why the need for OA at all ? Couldn't it be argued that the X factor is to compensate ?
Don't get me wrong, I'm all for the OA, seeing as I'm about to get a load of it very soon........