Youre making it way too complicated...
Keep in mind this is his first grow and he ripped the roots up early in veg. Try to put yourself in his shoes. I can gurantee no matter what you say your first plant didnt look as good as his, and its probably cause you tossed it out. I know mine didnt look that good.
With that being said, keep it up man!! If you can turn a plant around like that in a month then youre doing something right.
There would be nothing sub par about flowering this baby now. Shes more than ready. Youll soon find your worst enemy when first growing is feeling like you could do something more when your plant doesnt need it. The only thing id suggest is maybe a bigger pot. Your root system will grow more causing your plant to grow a little more. All plants stretch once you put them in flower, but this is mostly strain dependant.
You're right, but also wrong.
I did toss out my plants because I had a partner going into my first grow (Terrible choice) because he had the room, and I had the knowledge. I used his spare room for my grow op. Ended up with 4ft tall White Widows & G-13s using Fox Fox soil & trio nutes, they were super green and healthy till flower started.
The problem was my "Partner" decided it was cool to show everyone in the neighborhood the plants while I wasn't around, this includes turning the HID on at random times during the night cycle for an hour or two while they smoked in the same room then turn them back off. Then he started to take it upon himself to feed them when I wasn't around, only he thought more was better and didn't have any knowledge on anything about the plants and ended up burning them to death at week 4 so I tossed them and haven't looked back to him since.
I did however skip over the part where he mentioned he ripped the roots out, as I skimmed over and just looked at base information. So I can see why his plant was stunted, although, personally I would have tossed it and made room for a better plant since it was still super young.
Regardless nice looking plant since you had basically a 1 month setback.
I topped my plant 3 days before I put it into 12/12, once I saw two shoots growing I flipped. It grew fine, especially since I tied those 2 colas down, it made them into 2 big colas 2 mini colas off the same 2 branches.