You are correct that there isn't a project status filter in a Proof Approval or Document Approval report. I have a few pending proofs reports pulling 'pending decision' is true as the main filter. I caution against ignoring proofs in canceled projects, they should still have a decision of irrelevant/canceled/whatever you want to call a decision for that scenario. Even with a canceled project, if a proof is pending it'll still show pending. Then it's a slippery slope to have approvers ignore those as those build up. I educate my users that even if project is canceled, or completed, they need to make a decision to keep the out of their own and the proof approvers' queue. I send a monthly WF report to approvers with pending proofs as reminder to make decisions on proofs. Over time, the # of pending proofs has gone down.
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