Let's try to Lump 'em together...
From a PM, and not a Question, but a Clarification:
It is before Resolving Attack Effects...
Home One, for example, is an Attack Effect.
Admiral Ackbar, for Example, is an Attack Effect.
Quad Turbolaser Turrets, for example, is an Attack Effect...
So it only removes an Accuracy from your INITIAL ROLL. The moment the Initial roll is done, you're free to Add Accuracies and roll additional dice to get accuracies, without fear of removal.