The only clear picture I could find is of the hub with 2 triangular flanges I was talking about. They are also squared off on some cars. But I think you’ll get the gist of what I’m talking about from the one picture.
My best “educated” guess is that they may be for hooking all vehicles that are coming off the line up to test equipment such as line dynos. To test the performance specks of all the cars coming off the line.
But I just want someone who knows this answer to pipe in and let me know weather my guess is correct or not.
Many vehicles these days don’t have these, and most aftermarket hubs either smooth dish that area, cap it off, or square it off and not put anything there but their logo stickers.