There will be definite period of amortisation for your flying training, although this may only apply to PVR etc rather than advancement such as commissioning.
This period will have been defined by PMA and to be honest the best solution is to talk to your desk officer and/or trade sponsor (the deskie will in all likelihood go to the sponsor anyway for a comment on whether your trade can afford to lose you earlier than planned).
There are many factors at play - is your trade over/undermanned? How tight is the actual manpower vs the LUE at your unit? Is the Sqn accepting the 'gapping' of any posts of your trade?
At the end of the day, the working principle is that you should never be held back from trying to advance yourself - although I have seen this applied in a manner of ways.
Best wishes and good luck.
SBG