No extensions. The only extension would possibly have been for any new material filed when the base patent was still pending and not yet issued. That is not the case here and there is no extension available. None.

The 6 year rule simply says you can't go back further than 6 years for damages. If you file the lawsuit on the very day the patent expires, you'll get a 6 year look back period. If you file two days after the patent expires, you'll get 6 years minus 2 days. If you file on the 5th year and 264 days after expiration, you get one day of damages.

In other words, it's time to fish or cut bait.