That is NOT correct. You need support for any overhang over (IIRC) 8 inches, especially with stone. It's why many here get bamboozled into an 8" overhang, actually (and then they're sad that sitting there is uncomfortable).

If it's your fabricator telling you this, I would replace him. Who knows what else he "thinks" he knows.

It's my KD actually....

Only someone very inexperienced would even design an island of those dimensions in the first place, with bird on a wire seating, and with 15" of unsupported overhang. You need to look at a heck of a lot more details on this design than just the overhang.

It's not difficult to put in supports. Your fabricator just has to be ready with them. Here are ours. The fabricator had them cut and brought them with them when they installed my top. The supports are solid steel. They notched out a small part of the cabinet, which you never see because the top covers it. They are unobtrusive as we have seating around this area.

Debbi Branka - Thank you so much for the illustration that is so incredibly helpful. What a beautiful island BTW!!! What are the dimensions and what how big is your overhang?