A little bit of stress is fine, it makes them stronger.
And the optimal harvest time is as late as possible.
When I see how they do it in Aghanistan, entire fields of shriveled up plants, not the slightest spot of green anywhere, and considering how good that hash is I’ll follow their example. You’ll never regret harvesting late, so long as there’s no mold. I want a full on body stone, none of that heady nonsense.
My point is, why waste money on equipment if you can just wait until it’s obvious with the naked eye.