When pressed for a reason why, I have been told that because this is a very dense, hand routed design they are afraid of making a mistake and have required extra checking and sign offs which has slowed down the whole process considerably. They don't want to be on the hook financially for having to redo the whole order.
Am I misreading this, or does this sound like they won't be at tape-out until 30 days from now? (What careful checking of hand routed design will you be doing once the masks are being printed?).