I’m a little late to the party here, but figured I’d add this since I don’t see it represented.
volumetric speed mm³/s = print speed mm/s * Nozzle diameter mm * Layer height mm
So to figure out what value to plug into the max volumetric speed field, you read the suggested speed from the filament spool, and plug it into this formula.
For example, if my filament spool says 70 mm/s suggested speed and I’m printing with a .2mm layer height and .4mm nozzle diameter, then the max volumetric speed should be 5.6 mm³/s (.2 * .4 * 70)