David Shupe and I discussed this just now. There is a useful way that this could be implemented now, without any additional Firefly core work, that would meet the afw.display API and supply equivalent functionality, but based on clicking on buttons associated with "POINT" events rather than on keypresses.
The afw.display API should be extended to allow supplying an optional "name" argument that is used for the button label. The label should also include the key name that is mandatory in the afw.display API, e.g., the label might be "Variance (v)".
David Shupe will have to make sure that the x,y coordinates returned are exactly as in DS9, i.e., correctly taking into account issues of offset-0, offset-0.5, and offset-1 pixel coordinate conventions.