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According to USCIS, it takes adjudicators: (a) 0.51 hours (30.6 minutes) of touch time to adjudicate an extension of nonimmigrant status filed on a Form I-539; and, (b) 0.2 hours (12 minutes) of touch time to adjudicate an application for an employment authorization filed on a Form I-765. See 84 FR 62292.
The silver lining here is that it is much quicker to adjudicate a work authorization renewal case than to contest it in court. Hence, the Government has a strong incentive to settle viable mandamus cases brought to contest EAD delays.