Here is my version of the city of Tiresia, using the forthcoming Watabou Cities revised annual coming out in July.

I discovered one further problem with the drawing tools being applied to the imported DXF. Regardless of the import parameters, the walls remain as 2D polygons. The work around is to use the break command on each section. Click on the icon labelled x,y in the left hand of the screen, and select the object. Untick closed.

Then apply the drawing tool. This is the method I used.

Alternatively, just use the tool to draw the walls along the lines without using Change Like Drawtool command, which is probably easier. The lines will be removed when you delete the IMPORT sheet at the end of the process.

This is the result, for a fairly big city, using the Change Like Draw Tools command only.

And after a few alterations, I am designing the city more to my liking and fleshing out the surroundings, redoing the fields using the Drawtools to get field furrows aligned automatically with the fills from Sue's Darkland City. Did a demolition job to erect a large amphitheatre/football ground.