Since FFGO already announced that the company (and thus its shares) will go dormant after this deal and payment, I think the price drop after the ex-dividend date will be fast and significant.
So lets say the ex-divy date is 8/31, you need to have the shares at 8/30. After that you can sell, even if the actual pay date is at a later date.
In normal stock it's always best to accumulate shares 2 months before the ex-divy date if you expect a payment, because in the last month or so prices and buying usually go up considerably.