>>11066567finding metabolic pathways that allow for such rapid growth
You can change it all you want, but at the end of the day if your metabolism can't support it, you ain't growing any faster
some plants also don't give A FUCK about growing faster, if you give them a richer CO2 atmosphere they'll just grow to have less stomata because it doesn't need as many to capture the carbon it needs, and thus can use even less water