Hi
well altitude usually means a higher level of ultra violet light , thinner amount of oxygen in the air, and can make the resin glands more thicker to protect the plant...of course not in every case but in general.
My work in the mountains of northern India and Nepal some years back was fascinating. It seemed different slopes facing different directions towards the sun and away ,but in a 10km radius made a big effect on the hash that was being produced.Of course most of the time we rubbed Charas from living plants and for me it was the champagnes of the hashish world. I believe my photo of something I won a cup for when in Holland was borrowed by Rob Clarke for his book on Hashish. The technique takes years to get really down pat but basically we use to rub the plants in the heat of the day and clean away the green leaves and pistils to make cream charas. The principle is simple since resin is not soluble with water so as it heats up it sticks to other resin glands and the longer you rub the more resin begins to ball up and coat your fingers. Considering the green part of the plants all contain small amount of water they do not mix in to the resin ball so freely therefore cleaning them off the hands and keeping it all warm you end up with a very impressive 10 grams in a long days work.
But to get back to the point the strains mostly used are long spindly sativas which would explain the trippy psychadelic effect the hash produces in those parts ofthe world. If SSH, NH or Mango was made into a hash like this you would get a trippy piece of hash...and one I would like to burn with you.
Good luck in what and how you do it but those would be the strains you are looking to grow in altitude for that affect.All the best Sb