I am just going by my personal experience and what rhe locals tell me. Yeah the ganja they grow in the south is still grown in higher altitudes. For example Kerala gold as you mentioned is grown closer to Munar- altitude almost 2800 meters. Not as high as the Himalayas, but ive nver seen weed growing past 10, 000 ft
The local bud I get here in pune is grown in ths nashik region which is famous for being one of the few regions in india producing decent wine domestically. It is also hilly terrain.
As far as introducing artificially selected hybrids contaminating their native birthplace...thats a whole nother argument. Its going to happen eventually whether people like it or not. The farmers who make very little money from their risky operations are not going to give a flying fuck about preserving wild traits. They are going to realize eventually that indias gigantic growing middle-class is demanding better quality product. Besides how do you think hemp got to be? Its techinally the same species as ganja but has little to no thc. This is what happens when u let weed grow wild..it tends to lose potency with each generation.
Like I said I am reporting first hand experiences with local producers. I have travelled all over the country and know what is available where and for how much. I dont have any "data" per say from research articles so take what I say with a grain of salt.
Do you not realize that introducing genetics in the potential birth place of cannabis is criminal. "Contaminated by landrace", this one is brilliant, truly a gem.
The famous Kerala variety come from Southern India, nothing to do with the Himalayas.
"A different variety more indica dominant from Afghanistan is used and grown further south at much lower altitudes" where you have a more tropical climate, are you sure of your datas??????
Also the potency of the flowers is the potency of the trichomes which if you think about it is the potency of the Charas.