Probably not beneficial to make CO2 unless you have your plants in an air tight container; I think CO2 is pretty much apart of our atmosphere. I know what you are thinking, CO2 means more photosynthesis, but I don't think that the presents of CO2 actually induces a plant to even want to over-clock its self. It would need a lot of light with the right mixture of heat, humidity, and nutrients to go in rapid mode and I still don't find this to be scientifically proven to be sufficient. I think in most cases patience is a virtue.
for making CO2 in a gal bottle with sugar and yeast can u put more then one hole in the container to let out more of the CO2??? sounds like it would be a good idea to me...also how fast does CO2 fall? since the only space above the plants to put to container is over 4 ft above the tops of plants