In a brand that offers more than one proof i.e. OF 86/100, or WT 80/101 do they make the changes by adding water at the barrel, bottle, .. both, or are they separate runs all together?

I'm trying to compare OF 86 to 100 and as my ice melts in the 100 I think the flavor improves but it doesn’t really taste like the 86 at any point of dilution. Also I was reading the shelf tags hanging under WT 80 & 101 and they gave descriptions that were more involved than
"Ahh 80 it tastes like 101 with a splash of water"

John F