If I have a ship with TLT locked while using M9-G8 can I force a reroll on both TLT shots or just one because of the Attack header?

On both shots, like every other "passive" modification (meaning one that doesnt require to spend tokens)

Both.

Anything that happens " when attacking" or " when defending" (and doesn't have a once-per-round limit) can apply to both shots, but has to be triggered and paid for (if there's a cost of any kind) separately for each shot.

Anything that happens " after " attacking or defending only happens once, after both shots are done.

Thanks guys. Huge help