To be honest mate I've heard red stems blamed on everything, genetics, lack of NPK or micro nutrients, too hot, too cold, ph too high/ low.
In the end red stems means nothing, don't worry about it!
I would think, you are missing a quantified pool of specimens to even think about noticing plant specific traits in a strain... & if your grow is that big... well I'd like to be there to help out...
Whoops just noticed you said plant specific... it could be--gotta grow Em out to really know... take clones...
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