Published.
http://gimpscripts.com/2017/10/fake-voronoi/

It quantizes the source image, then on each colour area creates inward paths using an internally embedded service function derived from RobA filter "Mosaic Tile Helper".
The paths are stroked either with dots or with lines (two options at user's choice).
A layer with plasma2 clouds is added to overlay nuanced colours.
At end some other bits and bytes" are applied  for improving the result.

Two notes:
1.do not be bothered by some info messages you get on the error console during processing, they inform you that some areas have not been stroked because too small
2.try and look, not all images are suitable for such processing type.