nope.
what do you consider marginal? if a strain was 12% without and 14% with, that's hardly marginal IMO. for the cost of less than a single malt, i'm down with it.
This is simply not a debate I care to have, but if you can get 2% THC more just by adding UV then everyone would have done it... Consider, at 20% THC adding 2% THC is a 10% difference, meaning there is a cheap and incredibly easy thing to add for INCREDIBLE gains in THC levels. 2% is starting point by your "random" guess, meaning once tested thousands of times you can be assured that more than 2% would be possible... meaning that adding UV could add 10% to 30% more THC. Odds of you landing on that perfect level of UV on the first trial runs is almost non existent.
While I'm not saying that UV won't help, I'm suggesting you add to the pile of people that have used UV and show us where no one else has been able to, that having UV will give you such large gains.
We are in the LED section where the whole point is to create a better light through efficiency... Why grow with LED if you use the same watts but ends up costing so much more for the lights upfront with no long term savings? Consider that if a new CoB or diode came out today that offered 10% better efficiency over everything else out there how these boards would blow up... If UV added 10% more THC or better once tested over years then my feelings are that we would already know about it because UV is not "new tech."
What you're suggesting as a possible increase (2% thc with UV) is that on the low end 10% more THC should be possible with added UV. Meaning on the LOW END that's 1% more THC per 10% THC tested bud. At let's say a high of 30% increase in THC levels with added UV should make it 20% THC bud now 26%.. Again if tested over years you can bet people will find the best UV and times/levels and get higher returns... If this were the case, once again, we would know all about it.
30% THC bud would mean we could see 39% THC bud...
Again, feel free to try it out, do the testing to prove it works and go down in history as one of the greats. I'm being honest, I'd follow your work if you can show that it actually works. I personally don't understand how outdoor is not massively better than indoor on THC levels...