Greetings, fellow rules nerds! Someone has pointed out that the Aftermath step is commonly considered to be part of the attack (see: Torani Kulda + Captain Jostero). If this is true, then a B-wing that uses FCS to reroll an attack die could not then spend the lock during the Aftermath step to perform its bonus attack.
On the surface, this strikes me as exceedingly silly, especially given the devs specifically stating that this interaction (i.e. performing an S-foils bonus attack after using FCS) would be possible when they spoiled the S-foils on stream. Then again, I was one of the dissenters who thought (and still thinks) that the Aftermath step doesn't happen both during and after an attack simultaneously, so obviously I would have zero problem with FCS + foils working just fine. I wanted to bring this interaction to everyone's attention so that multiple perspectives could be shared and the conversation can
devolve into yelling
result in an amicable "FCS PLZ TELL US WHAT'S GOING ON, IN THE MEANTIME CHECK WITH YOUR TO" before the S-foils get released.