There is actually no deadline at all in filing the case. There is only a period of retroactivity of six years. So, the later you file, the lesser you can get.
The first 3 FAU cases were filed in 2008, so they can claim back the shortfall up to year 2002. And the cases were concluded in sept 2012.
The pre-07 and post-07 difference was mainly due to the change in formula in calculating the average daily wages - from looking back the previous month to calculate the average to looking back for the previous 365 days (/a year).
The FAU cases were mainly focused on pre-07 issue was because some of the elements to be included in the calculations was not clear and has to be determined by the court -- a matter of principle. The post-07 issue was mainly a matter of quantum. So, after the cases were concluded in sept 2012, it now turns to the amount of the claim which is what they should be dealing at the moment (for both pre- and post- 07 issue).