I'm a CAD/LibreCAD newby and I'm having difficulties understanding how to save text to a dxf file. If I create a diagram containing text and save it, the text does not render properly if I open the file in inkscape. I can draw various shapes, eg lines, circles, arcs etc, and they work. But text does not appear in the same location if I open in inkscape, and does not appear at all if I use a different font to the default.
I am not sure if I understood all you said, but may be it works if you print / export what you draw in librecad to pdf, save it as a picture (such as jpg) and then open in inkscape?
If you make pdf or jpg, everything looks right, as you draw in librecad
LibreCAD has its own Font format for easier and fast rendering.
So I assume, that Inkscape does not support this and is not capable to render LibreCAD LFF fonts.
You can try to create a SVG in LibreCAD, by using File -> Export -> CAM/plain SVG.
Or explode text before saving in LibreCAD. But this converts text into basic entities and you can't modify text after explode.
So it is recommend to keep original DXF with MText and use a DXF copy with exploded text for Inkscape import.