To be honest I still agree with the standardish 6"-20" above colas(temp readout below 80F), but it boils down to productivity. Daily too weekly I use to raise my lights, check ph levels on all counts, individually neem oil fan leaves(bad summer once, nip it in the butt before it begins), etc… 10-20 flowering plants. Results were great but what I’m getting at is if you’re doing a micro grow, test all methods as minute as possible. Bigger grows, go with diaries/info you learn from here and other such sites.
Cannabis is life, it always finds a way(yep, Jurassic Park)
Good luck, grow well
-Pool