Make a plant think it may die (stress) and it kicks into reproduction mode. The capsaicin is there to protect the seeds. So, stress could help for sure, but may I assume a stressed healthy plant? Stressed with sun? Peppers hot or sweet that I have grown have had their dicks knocked in the dirt from the sun at my house in Mexifornia. Perhaps a sunburned half dead plant with three peppers could be hotter, but that's at a high production cost. I intend to put up some shade for my peppers this year, but I will experiment with sun and shade on different plants of the same type. You are what you eat and the same applies to plants. Key Limes are not Key Limes if they are not grown in the Keys. A walla walla sweet onion grown in my yard is not the same as one grown in Walla Walla county in Washington. I ate at a very nice looking salad bar outside of Denver once and now I know why some kids don't like vegetables. Thy tasted horrible because of the soil and water that grew them. So, what needs to be in the soil to grow peppers hot? If Brix level is important what make an affective Trix level?
The Madonna thing reminds me of part of a parody I wrote, "...Beethoven is the fellow, Who can grow my leeks mellow, The corn prefers a rock an' roll band..."