Different laser cutter software need different formats and also different styles even with in the same file format. Traditionally lines have the width of the actual laser cut. Normal cuts are black and for quite a while now holes are rendered blue. But this is not the right thing to do for all use cases. One such use case was Ponoko - an online manufacturing service that does laser cutting. There the lines need to be thin and also need a different color scheme. wayn3w did not only add a new format - svg_Ponoko - but re-factored a lot of other code.
There are still several tickets open to optimize the SVG or adjust some details. Unfortunately the graphics library used (cairo) limits the things that can be changed - easily. But if you need different colors or line width settings this is quite doable now. Please speakup either here in the comments or - preferably - in a GitHub ticket.