I was recently trying to create a piece (linked here) using slanted extrusions. I wanted a 45° relative to the front view to create a new workspace to push the extrusion through. I was able to do that by changing the projection parameters inside property browser -> view but it would have been so much easier to do so with a graphical solution similar to FreeCAD's navigation cube, Fusion360's ViewCube or Blender's Navigation Gizmo

It could also improve usability and help with other issues such as (#123, #888, #325) nagivation and it relates to #956. It could potentially make changing the current projection parameters move discoverable and intuitive to use