It'll be in there. Would be silly not to. It all scales quite well. So far I know of runners who have run 2:28, 2:35, 2:48, 3:04 and 3:32 (and me 2:24). All were pretty big PBs, the best being the 2:48 as the guy had never even got close to breaking 3 in 10 previous marathons ( I will say though, at least 5 of his previous training blocks were the worst possible anyone could come up with). The main focus was on why it's going to work and getting them to buy in, and to not worry. The other big thing was about pacing. Again these are two big chapters I think people will like.
All had ran at least 3 other marathons before (except me, obviously my first). Those are the people I definitely know about, if there are others, they have done it without me noticing or helping in any way. I'm sure there are, the community is way too big now to keep track on. It was hard enough with only 500 people on Strava, let alone 4k, 2k+ on Reddit and this ever expanding thread.
Some caveats. All apart from Grandma's guy who (bar bad weather conditions suddenly on the day compared to the forecast) I expected would have gone faster than me, were running on scaled plans using time or relative distance, rather than 3x5, for example
The other point, they all have a minimum of 4 months training like this using the basic 5k-HM principles, some much longer. If you picked in the book as a standalone marathon plan, I think you might struggle and it'll probably potentially put you in as much of a hole as any other marathon plan could and it'll be just more of a question of, do you survive it?