Cursor Location in Leaflet SVG Layer

As the cursor moves over the SVG Layer its x,y values are shown, along with the associated map lat/lng points being computed.

Scenerio:
1). The map is placed into its DIV (width:800px, height:400px).
2). The map is centered at Lat/Lng (0,0) at zoom level 1.
3.) The SVG element is added via initPathRoot, creating the SVG layer
4.) An SVG rect background is added, along with circles at its center and corners.
4a.) The rect and circles show the SVG layer extent at initial loading.
6.) The svg viewBox is computed and shown. This SVG layer nicely covers the world map
7.) As the cursor moves over the SVG layer, its x,y values are shown. Uses svg methods createSVGPoint, getScreenCTM, and matrixTransform
8.) The cursor x,y values are then used to compute the associate map Lat/Lng values,via the map method layerPointToLatLng.
Note: These values are unchanged during map zoom level changes.
VB x:VB y:VB w:VB h:
Cursor Location:   SVG x: SVG y:    Map lat: Map lng:

SVG Source:

Javascript:
OK in:IE11/CH40/FF35