I have a Honey Peach CBD auto going right now that's 38 days from seed.
In one week it grew 26" in 7 days which is an average of 3.7" per day, 3 of those days it grew 4" per day.
I finally had to LST the top because I ran out of room to adjust the light.
It was at 59.5" tall when I bent it over and its grown at least 4" since then but its finally slowed down.
So well over 5.5' before it's done and it has a month to go.
I grew the same strain about 5 months ago and it reached I believe it was 49" tall but that was grown in a tiny 4 gallon fabric pot.
My blueberry autoflower were a good 3ft tall. Harvested 24.1 oz from 4 plants dried. They were taller that I expected for an autoflower and they went alot longer than the 8 to 10 weeks the breeder said. I harvested the first 2 at 12 weeks and got 8oz. I let the other 2 go 15weeks almost and got 16.1oz. Far exceeded what I thought I would get.