In my last kitchen remodel I got rid of unsupported/open overhangs on my island and end of my peninsula, because my DH and teens kept placing heavy stuff on those sections. They think stone is unbreakable and can float in air! ;-)

What a pity. That's a lovely piece of stone.

These are pictures of the overhang from my former house. Yes, I know the two tier island and backsplash are dated and therefore considered cringe-worthy... BUT I'm surprised I don't see overhang support like this more often. In addition to the corbels, there was a piece of wood (finished like the cabinets) that ran across the underside of the whole overhang. It also meant that the underside was smooth rather than rough stone, which I liked. I didn't ask for it; it's just something the cabinet maker did. Wouldn't that help make an overhang stronger, especially if it runs across the whole underside of a one-level island? (And yes, I know it made my counter taller, but we raised our counters anyway because we're tall.)