VLC ignores MKV color transfer tag and sets it to HD content transfer function for SD content

VLC Version 3.0.17.4

640x480 video file created with ffmpeg with these

-color_primaries smpte170m -color_trc smpte170m -colorspace smpte170m

Mediainfo reports it was successful in tagging

Color primaries                          : BT.601 NTSC
Transfer characteristics                 : BT.601
Matrix coefficients                      : BT.601

However, VLC ignores the transfer flag. This wouldn't be an issue, but it is setting the transfer function to BT709 for SD content, which is wrong.

So there seems to be 2 issues

1. VLC ignores transfer flags in a MKV file (possibly others, video codec makes no difference)
2. VLC automatically sets an incorrect transfer function for SD content. This causes the colors in the content to be off.