The AAO engages in de novo review of facts and law and will deny petitions on grounds never asserted by the initial USCIS adjudicator. [The Board of Immigration Appeals, unlike the AAO, has issued detailed regulations to govern its proceedings, including a regulation, 8 C.F.R. ?? 1003.1(d)(3), that eschews fact finding and only considers de novo ???questions of law, discretion, and judgment and al