This Thingiverse model includes DXFs of an extrusion-like profile optimized for 3D printing. I've taken it to the next level and made it printable in vase mode. At first, I just hollowed out the center and added a thin cut to allow the slicer to get in, but this made one side of the extrusion liable to spread apart under some loads. I then got the idea to extrude the same shape 0.2 mm at a time, but rotate it 90° every time. This eliminates the spreading problem. Replacing the square hole down the center with a 6-mm round hole should also improve strength.
vasemode_extrusion() takes two parameters. The first is the total height to render. The second is the intended layer height under which it will be printed.
Print in vase mode (of course) with a 0.8 mm extrusion width. 1" and 150-mm pre-rendered STLs (for 0.2 mm layer height) are included, as well as the OpenSCAD source and a profile DXF.
The author remixed this model.