So something ive been following today reading wise and would be differences in between my own past result and current is grow temps, but a stipulation here for a more accurate metric is leaf temp.
So a example of the discrepancy is say you take the old recommend āroomā temps of 78-82F using yankee measurements for say what was ideal temps under HPS, well HPS puts out alot of extra IR heat that gets absorbed by the plants so much so that even though room temps may been in those ranges your leaf temp in actually more in the high 80ās to low and mid 90ās or more even if the air isnāt. Now in comparison typically with more modern leds our leaf temps are a few degrees cooler than ambient as they arenāt producing that excess IR heat but when you compare say you had two rooms same light levels same air temps but plants under an HPS had leaf temps of say 93 degrees, and those under LED had leaf temps of 73 degrees, thats a huge friggen difference as far as transpiration and growth differences are concerned.
So guess thats one question for both you @BudSy and @Shadey what have your room temps been at but more specifically what are your leaf temps if say you have an IR thermometer on hand.
Cause to me with my more adequate and even air handling of current, having the plants run at a cooler than ideal leaf temp could be that factor, as the temps donāt warrant the transpiration possible to keep leaves cool at say higher light levels, but are instead limited by it.