If I may weigh in, I thought the article was useful not for numbers or a recipe but for illustrating principles a person might use in order to take a recipe from one gravity to another without changing the character too much. I didn't think it was offered as something I should try to replicate.
Some people say that when you go up in gravity, you leave the dark malts alone in order to prevent them from becoming overpowering. Others say to increase everything proportionally. Looks like the person who wrote this article favors changing the proportions.
As for whether the beer in the article is a session beer, 4.4% seems pretty low to me. Beneath Budweiser.
It seems to have a lot of body, though. The article gives an FG of 1.020, down from 1.045.
With my own stout, I've always gone from around 1.054 to a kegging gravity of about 1.016, assuming my numbers are anywhere near correct over the 6 batches I've made since 2004. I don't have figures for earlier batches.
I didn't know it was possible to start as low as 1.045 and end up as high as 1.020.
It's true I don't pay any attention to BJCP guidelines. I get a desire for a beer that has certain characteristics, and I try to reproduce what I'm imagining. My equipment is like my cooking equipment. I didn't buy an oven so I could cook other people's recipes.
I've never had a stout exactly like mine. I don't use a faithful copy of someone else's recipe. I started with an existing recipe and changed it until it was very different. I wanted something sort of like Murphy's but not quite as dry, and I wanted some body. Got exactly what I wanted, so it's a success.
As for what is a stout, I don't believe a recently-constituted organization that caters to a tiny hobby community has the authority to decide that for the whole world.
I feel like changing all my ingredients upward without changing proportions and seeing what happens. I can adjust it next time.
