Caldric's Stone Age is a Reskin of the base UI to a "Stone-like" aesthetic. Bottom Bar includes the "Double" Bar feature. Simple check "always show" and undock the Quickslot Bar of your choice, and unlock your UI to align it into the Bottom Bar Graphic.

As Turbine begins to release more information & more details on how to further skin additional UI elements, Stone Age will gradually update to include new Elements to come full circle and complete the UI transformation. Enjoy!