So guys, this is something I've been hearing about so I decided to research it.... Found potential uses for human health and more technological discoveries on types of UV-B output.
Basically, UV-A is UV that causes tanning and stretches the receptors for UV-B allowing it to absorb more easily, but you can over-do it with UV-A making it hard to isolate proper amounts of absorption with UV-B absorption. UV-A causes potential burning and damage.
Bottom line, there is a more intense version of an isolated healthy UV-B spectrum called Narrowband UV-B, which focuses at the 312nm range with almost no other UV nm range output. This is mostly being intended for human health, but can be used for plant health especially with Cannabis for THC production.
Narrowband UV-B is much different in effectiveness than silly reptile UV-B bulbs that can't compare. They are also costly as they are intended for human health. These can be found on ebay, and if you look at more items from the dealer you can find higher wattage units.
However, as for stressing plants for THC, I can understand how certain forms of stress would create more as THC is a defense mechanism production. Things like Dry, Hot, maybe some other forms of stress, may cause more THC production...
But, UV-B influence is not a stressor, it is directly related to providing a nutrient the plant needs to create the THC for various stress factors (Just as UV-B is what creates the vital vitamin D in our skin).
Keep this in mind... So for optimal THC production, you could influence the plant with Narrowband UV-B and also provide a hot and dry environment. Providing the necessities (air/water/feed, etc) are still required to even produce the THC... Unless the plant could also use it's own energy to also produce more if you used that as a stress factor - near the end of flowering.
Eh, what do I know