Any FTRS time is non-consolidated and does not go towards any pension rights you may hold.
Also, check the T&Cs of your engagement. Some jobs do not have an "X-Factor" in the pay and as such will be less than your rank counterparts. Typical jobs would be a unit PSAO or an SO post which is time-barred or project based. I heard there was an SO3 job at RMAS which was an 18 month slot delivering an IT project to aid OCdts in learing G1 as part of the course. This would be minus x-factor as it does not have a call-up liability.