ps.map ommits vector boundary/line where it overlaps with map frame
If I add a vector layer in ps.map which contains vector boundaries that overlap with the border of the map frame, and deselects the option to draw a border around the map frame, the part of the vector boundary that overlaps with the map frame border is also not drawn (compare A with B in the attached image).
Not sure it helps, but if I save the map as ps file and open it in Inkscape, that part of the boundary still seems to be missing. However, when I ungroup the map (you'll need to select ungroup several times), the boundary shows up, so it seems hidden rather than removed/absent
Example where