“who approved the warrant “
No, I’d just want to know how much the dossier itself contributed to the decision. No justification required. They supposedly answered this question in the committee hearing, but since the hearing was classified, transcripts cannot be released.
Incidentally, keeping it to that one question won’t required a classified answer, as it is already known the dossier was part of the application.
A judge would almost certainly answer that the decision was made based on the totality of the application, not a part of it. That would lead to media claiming the dossier didn’t matter.
A way to shed light on the issue might be to review the application that was turned down in mid-Summer 2016. Based on timing, it likely did not contain the dossier itself. Compare that failed submittal with the one subsequently approved. Since the second try was approved, any difference (for instance adding the dossier and Isakoff article based on the dossier) would be a strong argument that the new material made the critical difference.