So this came up today and we played it as rerolling an accuracy does not unblock a defense token and rerolling into an accuracy is useless as you have passed your chance to spend them to block defense tokens.

Basically we looked at the flow chart for attacking and since you mod attacking dice -> spend accuracy results -> spend defense tokens, and all the defensive reroll forces we can think of happen at the Spend Defense tokens step (Evade, Lando), which is after spending accuracy, we both cant reroll an accuracy because it was spent (thus not there anymore) and a reroll into an accuracy might as well be a blank since theres no window to spend it.

But i got this nagging feeling that was wrong. And im having issues finding a better explanation in the rules. Any help would be appreciated.

Seems you've got it.... Simple.

In order to Block a Defense Token, you must SPEND the Accuracy.

At which point, the Die showing the accuracy symbol is REMOVED.

ITS IS NO LONGER THERE TO BE REROLLED.

So there's no such thing as "unblocking" a Defense token. It simply cannot happen - ECM is the closest effect to that...

And then, for the Defence - yes, if they reroll a Die into an accuracy, the window is passed and it cannot be Spent ... Hope its a Blue Die with SW7s equipped....

One extra caveat that I'm sure you got right, but better safe than sorry.

If the attacker is rerolling dice during the Modify dice step (Leading Shots, Vader, CF token, etc) any accuracies they get from those rerolls are valid to spend to block a defense token.