Don't know the code, but this is from a GE install manual. It might help a little. Usually, from my limited experience, the inspector requires the item to be installed per the manufacturer's instructions.
If cabinets are placed above the range,
allow a minimum clearance of 30
″ between the
cooking surface and the bottom of unprotected
cabinets.
If a 30″ clearance between cooking surface and
overhead combustible material or metal cabinets
cannot be maintained, protect the underside of the
cabinets above the cooktop with not less than 1/4″
insulating millboard covered with sheet metal not
less than 0.0122
″ thick. Clearance between the
cooking surface and protected cabinets MUST
NEVER BE LESS THAN 24 INCHES.
The vertical distance from the plane of the cooking
surface to the bottom of adjacent overhead cabinets
extending closer than 1″ to the plane of the range
sides must not be less than 18″. (See the Dimensions
and Clearances illustration in this section.)