That’s what I thought too. When you say “whenever needed” do you mean based on the tire-gear selection or on a car by car basis? I’m sure they had to know ahead of time which combos would require one and what ratio box to install. Most I’ve seen are the .8241 ratios on 70 Camaros. The F60 tires were new in 70 and I believe they didn’t have the selection of internal gears to set them up right. I think the metal drive gear was only a 9 or 10 tooth. Later they had a better selection of gears and did away with the box, especially when the moved to the T10 in 74The Wiki isn't always right. You are correct, there would be no difference between close ratio and wide ratio as the output shaft is what is measured.
My 70SS with 3.31 gears has a ratio box on the Muncie. They were used wherever needed to make the speedometer correct.