I'm not aware of any deadline as long as there is a stay on the CDL suspension because there is no prejudice to the driver. There was a time when DMV would set aside the suspension if they didn't have the reports in 45 days but that hasn't happened for many years.
Technically, so long as they have issued a stay of suspension, it can be indefinitely until they get all documents they need to proceed. In San Bernardino Driver Safety, the continuance is typically 1-1.5 months at a time. However, a good attorney with working knowledge of DMV procedures and good relationships with the Hearing Officers can sometimes work out a straight dismissal after 1-2 continuances for failure to obtain reports.
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