According to DW at last night's meeting, if the company announces that they are lowering the BLG to prevent a furlough, they can do so. They haven't done so yet, that is why they are buying up the lines that currently go below 68/85. If they do announce, they can go below to any number between 68 and 48 (4 week month). They must go done to 48 before any furlough occurs.
He said in June the company paid $5 million to buy up lines. He also said that if the company made the announcement now, they would only need to drop the BLG down to 64 - 66 hours to make the manning issue correct.