Install the steel,. No point should be unsupported for more than 24", and the corner is especially vulnerable to breakage. The steel should be a minimum of 9" deep from the cabinets.

But that would be a much better design with a post at the corner, and stretcher bars, with steel ladder, for a table type overhang, since you can only seat 2 people at it max, anyway. Without that type of post, it's going to look ungrounded, floating in air. That type of thing only works with a level change, and a very Modern look.

Thank you! Design aesthetics aside, are the steel supports drawn in blue sufficient?

As long as they are not flat thin steel that is bendy, sure. Tubing is the better option, always. Still don't like the design without the post and stretchers though. Have you had anyone create a visual of this for you?

The brackets on originalgranitebracket.com are 1/2 in by 2 1/2 inch - in your opinion, is that thick enough?

Yes- it is pictured here with a leg vs invisible support brackets. If I kept a leg, as pictured (without adding stretcher bars, just a leg), would I still need additional steel support?

The bracket on the right side and the skewed bracket, how will they support anything being that short?

"Design aesthetics aside, are the steel supports drawn in blue sufficient?"

No. You can't just screw a bracket into the top of a cabinet and expect it to do any work.

You need a custom built 1" square tube steel frame let into the cabinets. Have the welds ground, paint it flat black, and it will be inconspicuous.

If you can't walk across your underlayment, it's inadequate. The top is just a veneer.

How do you expect a post to stand vertical in thin air unless it has stretcher bars attached to it, to attach back to the cabinet?

I appreciate everyone’s input, and I also appreciate kind attempts to help me understand what is needed - that’s why I posted here, because I don’t have the knowledge needed to make this decision indepndently. The input I’ve received so far includes the following options:

1. from my cabinet maker: flimsy braces from Amazon.

2. from my GC: custom welded steel support arms that will cost $700-800

3. from my research and reading MANY threads here: custom bracket from https://originalgranitebracket.com/products/custom-support-brackets

4. from this thread: a post with stretchers (and possibly additional steel support)

5. from this thread: custom 1” square tubing set into the cabinets

6. from this thread: steel support that extends 9 inches out from the cabinets but isnt too flat. (I’m not sure if #3 is this, or if #5 is this, or both).

I’m not willing to do #1, and hoping to avoid #2. I appreciate any kind opinions on both what is sufficient, and what would be ideal. I also don’t have the bandwidth to seek out a local iron worker to custom make square tubing - is that something I can purchase somewhere?