Keymap: E - Extrude Gizmo supported. If the extrude points are the first or last of the stroke, the stroke is extended. If the extrude points are in the middle of the stroke, a new stroke is created because the grease pencil strokes can be only with 2 extremes and fold the stroke to get a new point gets very bad results. Still pending define a new icon. Also, it could be good to set by default XYZ axis in the gizmo. Note: There is a change in the transform_gizmo_extrude_3d.c gizmo for OB_MODE_EDIT_GPENCIL. This change must be undo when the mode will be integrated into OB_MODE_EDIT, but while we have both modes, we need to keep this code in order to keep running the gizmo.