I understand (now, thanks) that the "typ." and "max." values for VF are not only individually different, but may change over time for a given led.
The 'typical' values are not only individually different, but may change over time for a given led.
The 'maximum' value will not be exceeded by any led at any time (unless you abuse it).
It it usual that VF will grow with age ( making current decrease in a given resistor controlled circuit )?
In many applications this is of little consequence since the LED current can vary over a wide range without the amount of visible light, as perceived by the human eye, appearing to change.
Don