Drill down and up buttons are hidden by default. The user needs to hover in just the right place to make them appear. Sometimes it's hard to find that place, and most of the time users just don't even know it's there. I'd like to have an option to always show those icons, to make it easier for users to find and use this feature.
Agree with this idea and all supporting comments! It would be much more intuitive if the button remains ON.