I'd like to cut the pattern (or cut the fabric directly) on a laser cutter.
I need to be able to set an etch mode for the sew lines and the pass marks, and a stronger laser intensity for the seam allowance cut.
Most laser cutting interfaces let you apply the settings according to the colour of the lines in the SVG file.
(Apologies if this feature already exists; I've looked hard and couldn't find it. You can set colours of curves and lines in the drawing mode, but I couldn't find such features in the layout mode. )
Different line widths in the output (or different styles, like dotted) would also make it possible to distinguish between the line types if colours are not wanted.