Rumpole
Formerly known as "Hercule Poirot"
No. They can't hold back the evidence. But they can't disclose things they don't have yet from the FBI, and they don't necessarily disclose things in a timely manner even if they "have to." But they are not holding things back from the defense in hopes that the defense will not have time to effectively respond by the time it is disclosed, because the judge will never let that happen. If they try to bring in something new at trial, it will be excluded. If they try to bring in something new too close to trial, the judge will reschedule the trial.
Without "holding back" evidence surely Prosecution can decide what order to release documents in?
We have have had around 6 -7 K pages so far, a certain amount of work is necessary to format, check etc for release.