https://edis.ifas.ufl.edu/pdffiles/TR/TR01000.pdf

This is really good. All about commercial production of peppers in Miami.
Good descriptions of all the pepper varieties.

This little thing stood out. I don’t know if all growers do it but they said “For chili peppers, 2 or 3 transplants usually are placed in the same hole because of their small leaf area. “.

Never heard that before.

Also didn’t know that “habanero prefers a slightly acidic soil (about pH 6)”.
I wonder if that would be true for scotch bonnets as well. My soil generally has high pH though it fluctuates.

I've always thought that all peppers preferred slightly acid soil, in the mid 6 ph range. And scotch bonnets are another C. chinense, as are habaneros, so I'm sure that they will do better in the acidic soil, as well.

I have never planted more than one plant together. Maybe this was for some small varieties, but even with those, the plants usually get so bushy that it's hard to get to all the peppers! But commercial growers probably grow some determinate types, which they can plant much closer, let them all ripen, and mechanically harvest them, like with bush beans. But I'm just guessing.

I agree with you, my scotch bonnet plants were huge. Can’t imagine 2 or 3 in a hole. If it did work it would be interesting to do 3 different peppers. Sorta of like one of those grafted citrus trees with 3 different varieties.