This patently false. Plants use co2 throughout the entire cycle for photosynthesis, increased photosynthesis means increased growth. Where you get this notion not to use it in veg is beyond me. Dr. Bugbee has lectures on this very topic invalidating pretty much everything you’ve said.
I use co2 from seed at 1200ppm all the way to harvest.
Again more rubbish, you won’t hurt your plants.
Yeah I kinda agree, it was a bit of an absolute written by me, what I mean is. In veg, you don’t see that much of a difference in growth between using co2 and not using it. If co2 is hard to obtain or it costs a lot of money. It’s not worth running it in veg.
Using more ppm that your plants can handle plus not using a controller in a closed environment, will cause co2 buildup. This will sufficate the roots and it will kill the plants.
Pz 
I always cut the co2 off for the last two weeks of flower. It’s great for fast growth but it will affect the quality of the bud if used until the end.
The Result:
After five years, the willow tree had grown significantly, yet the weight of the pot and soil remained nearly the same. This observation led Van Helmont to conclude that the plant’s growth must have come not from the soil but from something else absorbed through the air and water.
C02 baby
Again you are making unsubstantiated claims. Using CO2 in veg increases photosynthesis as well, and increases the speed of growth - why do you think it would be any different in flower? 
Judging based on some of the information you have released here I get the distinct impression you rely more on anecdotal accounts/information than scientific facts.
Please enough of this bro science.
Yes, it does increase photosynthesis. I haven’t said anything else, but the increase in growth is not as noticeable as the increase in quality and yield. I’m sure you can run it in vegative to as much as 1600ppm if you have good access to co2 and a proper setup. What I’m saying is that if you don’t have a good source of co2, veg is a good way to save the co2 until it really matters.
Pz
Joins 13 hours ago and goes on a spell accosting Prior members.
Oh please Edgelord tell us the errors of our ways.
lol yeah these types seam to come in waves 🤦
He knows better than anyone here please enlighten Us with your peer reviewed White paper research results??I got to see this one 
Looks like we have a Dutch Master in our presence.Watch out we have a badass on our hands
If your rooms sealed then you have to use co2 in veg.
I commented before I finished the read.