Citrus Rush flipped 26 days ago. Ended up flowering out the strongest looking 3 of 6 females. The best looking one so far in back right was also the only one of all 6 that didn't take root easily. They have a nice sweet smell with a hint of citrus so far, not the most pungent type of smell but...
How far away are the lights? Sometimes the plants can wilt at the end of the day especially in veg under 18 hours when they are getting a lot of light. Is your temp probe in direct light? I would think with an outside tent ambient of 20c you could set your controller to 27c and 65% rh for now...
Looks like the study was done with LED
https://www.researchgate.net/publication/236189497_Photosynthetic_response_of_Cannabis_sativa_L_to_variations_in_photosynthetic_photon_flux_densities_temperature_and_CO2_conditions
A passive intake should be 3-4 times the area of the exhaust.
https://www.acinfinity.com/blog/what-does-passive-intake-do-in-grow-tents/
So your 6" exhaust is about 28.27 square inches x 3 = 81.81 sq inches which is roughly a 9"x9" square or 10.2" diameter hole or just three 6" holes
+1 on photo are they full on drooped over or just kinda droopy? Maybe too much light? Sometimes certain genetics are hard to take root and it's more like 14 days instead of 7.
Interesting, would you just pick the ones that looked the most loaded with trichomes or parts of the biggest colas? Sometimes the smaller nugs seem to be more dense with trichomes.
Are you running lights on during the coldest period of your day? Your outside room / lung room can control much of the grow temp with vent cycles unless of course it's also hot.
The high thc strains are kinda boring in a way, one dimensional I guess you could say. Some of those old sativas with a lot of landrace dna still in them get your mind soaring and it's gotta have good flavor.