despegue - I know nothing of the Boeing 'recommendation'. Most airlines insist on F40 in 300m or less since the view is better (lower nose angle - nb 'approach angle' is always the same for F30 or 40). It is reckoned you will NOT see the necessary visual cues in 300m or less with the higher nose angle.
HOWEVER - do what your OPS manual says! If it is to change, Boeing will tell everyone.