Since you’re scanning through the joblog of the save, the amount of pages will not matter if you use F16 on Find parm of the spool report.
Just enter the characters you’re looking for. In your case, enter the name of the particular library then press F16. This will bring you to that library in the report. Then enter “not saved” and press F16 again to see the objects not saved for that library (if any).
If you know CL, then just MONMSG for the CPF error and have it sent to your MSGQ, email, etc.