To go back to my metaphor, the difference between someone going "you should use a 2.4mm posidrive for that 2.4mm posi-head screw" when a 2.5mm will work, and someone going "you should use a hammer, not the back of your screwdriver, to hammer a nail"
Like, former one is not gonna affect anything and it's being pedantic, the latter one you're actually being helpful.