old post but helpful...
So, I must set the extruder higher because the most important thing is the pressure that you apply, and off course that depend on the density of the material...
I did some nice printing with 2x the value.
You can calibrate as well, just extruder like 50 mm and measure it.
I have calibrate as fine as i could do.
The best way is to calibrate and extruder 2x (tow times) the "normal" value.
We are injecting a hot material so, if you inject very hard it gets more compressed and more strong...