Thank you for your reply.
The instructions are a bit on the light side. For example the different options for each generate type are not specified.
For example, for hatching, what does levels count do? smooth, spacing, segment length?
For edges, what does t min and t max do?
Also, I'm getting inconsistent results. Especially on the lighter parts of the portrait. Sometimes it's etched, sometimes it isn't, using the same gcode.