I hope when the rollbacks happen, it's not just totals of 30M and above are looked at, but the time period in which the credits was earned. e.g a 100M+increase in assets or credits over a 12 hour period is pretty suspicious.
So check assets/balance pre 2.4, check again 12 hours later and if it's over a threshold reverse the credit gain and remove any assets obtained in between times
It is possible to earn something like 14-18mn credits per hour doing cargo runs in an Imperial Cutter, so 12*14=168mn is entirely possible and legal (though you'll be goggle-eyed and bored to death by the end).
Of course, if you were doing that in a Cobra Mk III....