I am used to using volumetric extrusion in Slic3r and now trying in Cura. I slice and save gcode to SD card, and print from the card.
In Slic3r when I select volumetric extrusion, it calculates extrusion based on a filament diameter of 1.128379 mm. Before I print the gcode I enter the actual filament diameter into the printer's controller using the LCD panel/rotary encoder. The gcode file can be used with any diameter filament, as long as I enter the diameter at print time.
What exactly does Cura do with volumetric extrusion? If I enter a filament diameter in Cura will it be ignored or w