Not directly related to the pivot UI issue, but to Sculpt Mode UI in general: I’m currently exploring the Blender Atelier: Sculpt add-on for a BlenderNation review (Cubebrush link, Blender Market link). It provides an impressively comprehensive expansion of the Sculpt Mode tools, and includes customizable Sculpt Mode UI elements. Here’s the manual if you want to check out the features.
I’m using Originie, by @kkar. Offers lots of pivot auto-placement options.