i will have to look in to that.all my life never have a seen somebody do it that way.especially that 30rh sounds super wrong, is this all just your experience or is it backed up with some research?
i know in hydro just because its hotter her ppm doesnt drop to show she is starting to eat it goes up saying its just water evaporating.
RH and Temp must be intertwined, if you set your RH to 30 you need to set the temp to 22-24c in order to keep transpiration rate optimum for that setting.
This is experience and nature, the best weed in the world is in places that has these climates.
The cold dry days and night in late flower in the Indian mountains for instance.
The 22-25c temp and 30RH will give you best quality if applied at the right time.
Not talking about yield or density.
30 degrees with 75 or 80 RH would give you a vpd of 0.4 - 0.21. This is definitely not what you want in flower. Optimal VPD for early flower is 1.1 and 1.4 for late flower. You are giving extremely bad advice by telling people to run 80 RH. This would be ok for clone/seedlings but definitely not for flower.
I'm not sure what you consider to be a successful grow but in hydro with optimal VPD and good nutrition you can grow a 2 pound+ plant under a 600 watt led.
Again my friend, get out of the charts and start looking what is best in the real world, each temp has the best rh setting for it but no one is saying in which to grow what, it's only references.
So, if you know anything, you know that optimum conditions are 30-32c with rh of 80 at least.
This is backed by science, not advice, look it up.
This is mainly for flower yes !
Where on earth you see people flower outdoor in 20c ?? Is flower started to happen on winter or something ?
Flowering is a spring/summer event, and as such it goes with heat and humidity yes to your surprise...
So again, if you can maintain a 30c with 70-80rh your golden for a massive yield, growth, etc.