Support proper visualization of sanitized through hole pads in pcbnew

This is a request for a new feature, if possible to support. Probably this will make more sense for the new 6.0 version, don't know. Currently KiCad pcbnew displays through hole pads in all layers, no matter they are sanitized pads or not. Sanitized pads only have a pad in the top and bottom layers typically, and they are normally used for high speed signals SATA, USB 3.0, PCIe and so on, to avoid these internal pads from acting as stubs.

Description

This not a high speed signal board, but I've sanitized pads in the library, due to a mistake, anyway they serve as an exampple. The first image shows a 4 layer board visualized in PCBnew at layer In2. Cu. As it can be seen the pads seem to be present in this layer.

However they aren't... If we look at the exported layer in PDF format, we get only the holes where the through hole passes through.

Steps to reproduce

Create a 4 layer multilayer board
Import a library component with through hole sanitized pads in the PCB project
Visualize the non-existing pads in the internal layers

KiCad Version

Application: Pcbnew
Version: 5.1.9-73d0e3b20d~88~ubuntu20.04.1, release build
Libraries:
    wxWidgets 3.0.4
    libcurl/7.68.0 OpenSSL/1.1.1f zlib/1.2.11 brotli/1.0.7 libidn2/2.2.0 libpsl/0.21.0 (+libidn2/2.2.0) libssh/0.9.3/openssl/zlib nghttp2/1.40.0 librtmp/2.3
Platform: Linux 5.8.0-44-generic x86_64, 64 bit, Little endian, wxGTK
Build Info:
    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: 7.68.0
    Compiler: GCC 9.3.0 with C++ ABI 1013

Build settings:
    USE_WX_GRAPHICS_CONTEXT=OFF
    USE_WX_OVERLAY=ON
    KICAD_SCRIPTING=ON
    KICAD_SCRIPTING_MODULES=ON
    KICAD_SCRIPTING_PYTHON3=ON
    KICAD_SCRIPTING_WXPYTHON=ON
    KICAD_SCRIPTING_WXPYTHON_PHOENIX=ON
    KICAD_SCRIPTING_ACTION_MENU=ON
    BUILD_GITHUB_PLUGIN=ON
    KICAD_USE_OCE=ON
    KICAD_USE_OCC=OFF
    KICAD_SPICE=ON