Okay if u dont’ have it, then u would have to do say 6-7 test shoot. to get the setting right, not to mention getting the lighting in the right position.

if u use it…then it’s bang! and u can adjust if u want to so u will be doing like what 3-4 test shots…….then the rest adjust the position of the light stands, which can take a lot of time

It’s basically reduce the time that u need to much around, cuz i rather spending time changing the position of my lights to play with shadows than getting the camera to the right settings.
It doesn’t mean that u hae to use what the meter says - u can change it, but u are changing from.