I'm wondering if you shouldn't have different rules for hardware than for software? For instance, what if somebody told him Apple had patented indented buttons and he couldn't use them? I see lots of good improvement ideas here in the comments.
Actually tooling up all these parts will cost him $100,000 before a single person can "try" one - so obviously he needs all the suggestions he can get before that stage.
Or, maybe "Show HN" is just better suited for software?