If it inserts past the top tube to the minimum insertion line on the post it's fine, there plenty of room for that and without seeing the way that boss is designed there's no way you can just assume those bolts will make it inside the seat tube in the first place. Beleive me it's adequate.... they wouldn't want the warranty issues. If you buy the right size frame to begin with you don;t need a lot of adjustment on a road bike post it never gets moved once it's set.
