It is fine if the judge is specific about each piece of evidence he wants such a certification for, and with the understanding that the DOJ is not going to certify any evidence that had ever been submitted in the lengthy case if that evidence is evidence the DOJ now rejects. The only evidence the current DOJ team needs to defend is the evidence of prior DOJ errors which caused it to drop the charges.
The FBI can work amazingly fast and accurately, lime when they analyzed tens of 1000s of Hillary’s emails in 48 hrs proving no violation of any security rules or laws just in time for the vote in 2016. Some of their most impressive work to date (that we know of)