With that setting, the nozzle now extrudes 80% of the plastic as it did at 1.1, which will go a long way toward reducing the overstuffed walls that caused visible defects.TomR wrote:The value I got for the extruder multiplier is .87
With a 2 mm wall and a 0.42 mm thread width, try slicing the model with 1 perimeter thread and 90% infill. That should give you a nice outer shell, nearly solid infill, and better mechanical properties.
An object made from layers of plastic will always fracture more easily between the layers, so the trick is to build something that's Good Enough. Higher extrusion temperatures will improve layer-to-layer bonds, while affecting thread width and infill properties... but now you have a good starting point!