Selling application for brand / Brand Gating

After going through 15 articles with conflicting details, I'm hoping to hear from anyone who has successfully gated a brand or even a single ASIN on Amazon like the images attached. If you have direct experience with the process, could you share some solid information on the following?

- Requirements or prerequisites for Brand Gating

- Specific information Amazon needs to expedite the process

- Any fees or potential issues associated with Brand Gating

Please only reply if you have personal experience with Amazon Brand Gating. I'd appreciate any real insights, as there's already too much conflicting information online—answers based on firsthand knowledge would be incredibly valuable (generic internet info just adds to the confusion).