feature request: Snapping in footprint editor

I want to design a footprint with lines that are not on the grid. For instance I want to place a rectangle on F.CrtYd that is 0.15 mm bigger than the rectangle on F.SilkS.

Currently I have to do this:
-Draw 4 lines on F.CrtYd.
-double click on each one, and then edit the line segment properties

What I would like to do is:
-Draw one diagonal line on F.CrtYd.
-Double-click on that line, edit the endpoints so the 2 points are 0.15mm off grid.
-Enter draw a line mode, and snap on the off-grid endpoint. Now the cursor snaps on the grid, so I see a straight line that starts from the off grid point, and end on a grid point. The line is now not a 90 or 45 degree angle.
-Press CTRL. Now the line is restricted to vertical, 45 degrees and 90 degrees. For a vertical line, the cursor snaps vertically on the grid, but not to the horizontal grid, so it can land on coordinate x=10.15,y=12.00
-When the user makes a vertical line using the ctrl key with x=10.15 and then goes near a horizontal line where y=13.45, the cursor should then also snap to x=10.15,y=13.45

I think the footprint editor can snap by default on objects in the current layer, and optionally snap on objects on all layers. This can create a problem when there an object that is very close to the grid. If the user is zoomed out, should the cursor snap on the grid, or on the object? If the user is zoomed in, there's no problem, the user can just see what he is snapping to. Can a user choose this by pressing a key like shift or alt?

Versions:
Application: ModEdit
Version: (5.99.0-223-ge291576c3-dirty), debug build
Libraries:
    wxWidgets 3.0.4
    libcurl/7.66.0 OpenSSL/1.1.1d zlib/1.2.11 libidn2/2.2.0 libpsl/0.21.0 (+libidn2/2.2.0) libssh2/1.8.2 nghttp2/1.39.2
Platform: Linux 4.9.196-1-MANJARO x86_64, 64 bit, Little endian, wxGTK
Build Info:
    Build date: Oct 13 2019 09:16:33
    wxWidgets: 3.0.4 (wchar_t,wx containers,compatible with 2.8) GTK+ 3.24
    Boost: 1.71.0
    OpenCASCADE Community Edition: 6.9.1
    Curl: 7.66.0
    Compiler: GCC 9.2.0 with C++ ABI 1013

Build settings:
    KICAD_SCRIPTING=ON
    KICAD_SCRIPTING_MODULES=ON
    KICAD_SCRIPTING_PYTHON3=OFF
    KICAD_SCRIPTING_WXPYTHON=ON
    KICAD_SCRIPTING_WXPYTHON_PHOENIX=OFF
    KICAD_SCRIPTING_ACTION_MENU=ON
    BUILD_GITHUB_PLUGIN=ON
    KICAD_USE_OCE=ON
    KICAD_USE_OCC=OFF
    KICAD_SPICE=ON
    KICAD_STDLIB_DEBUG=OFF
    KICAD_STDLIB_LIGHT_DEBUG=OFF
    KICAD_SANITIZE=OFF

PCBnew is being debugged in Qtcreator