codamedia, I think you are misunderstanding the MySQLi Extension.
Data Bridge, Design Extender and eCart are not yet MySQLi compliant. that us the next project
Adobe have deprecated the Server Behaviors which are the groundwork used for building the database functionality in Data Bridge, design Extender, and eCart. So we first needed to recreate that ground work which is the MySQLi extension.
Now that the MySQLi extension is released, we will be starting to work on migrating Data Bridge, Design Extender and eCart.
Data Bridge is the first one we will start on. as it is the most database driven of the extensions it will take the most time to complete.