Hi Slashee, the top edge, jus tlike all other outer edges, have been filleted, hence the rounded look.
And the edge on top is as it was designed in Freecad, so no issue there.
No, the size of the nozzle is not an issue although it is nice for you to mention that: I will include that in future Cura projects.
Where do I find, or how to produce, the gcode file?