Higher temps and higher humidity (and more light!) are a must to get the most benefit from co2 supplementation, but there are caveats. Yes, these conditions lead to increased growth but we must ask ourselves: what kind of growth?
If you want larfy buds and stretchy foxtails, then a good way of getting there is with high temps and choking humidity levels that prevent your plant from cooling itself via transpiration. You’ll get a lot of growth… unsellable growth.
For this reason I would recommend high temps and high humidity for only the early stages of growth, perhaps up to week 5 or 6 (assuming cannabis), before ramping down to more gentle/ordinary conditions.
The article implies that maximum growth (for Aspen) occurs at around 36C (97F) which I hope nobody decides to follow in their rooms. This temperature is acceptable for ordinary growth in desert hoop houses where low humidity and normal light levels (and atmospheric co2) limit the plant’s ability to grow wacky, but in high humidity indoor rooms with high light and co2 this is asking for trouble and a potentially ruined crop.
While I don’t have any studies to prove it, I would suggest limiting your max temps to 30C (85F), where that is the upper end of the differential, with gradual reductions each week, ending in the mid to low 70s(fahrenheit) by harvest.
If I were growing in steady state conditions I would probably opt for 25C (78F), with around 1200ppm co2, 64%RH, assuming very bright light. If any irregular stretching was occuring at the tips then I would back off light levels and humidity by about 10%, or find a strain that appreciates my growing conditions.