Today i decided to add the 2 new buttons that were recently added to TinkerCAD. Fortunately these two operations were both implemented already, so adding the buttons was a breeze.  The one with the arrow  implements the "D" feature that drops the selected objects to the workplane. The other one adds a workplane to the base of the object. It places it so that it is already dropped t the workplane, and the orientation of the plane matches the orientation the object was imported as. There is also a keybinding for the new button "E".