Interesting. I went to Modica some years ago – more than 10, I think – and at that time there were only 2 or 3 chocolate shops, at one end of town. What made Modica such a treat was the lack of tourists and touristy things, although already there were some lovely tourist accommodations, inspired by tax incentives the local government had given to young people to turn any large family property they had inherited into b&bs rather than sell them to Mafia-connected enterprises who laundered money/ kept gangs employed via real-estate/rehabilitation scams.
At first I didn’t like the chocolate, partly because my initial tastings were modern flavorings using hot peppers, salt, etc. But it has since become one of my Italian favorites, especially the orange-laced. It is not easy to find elsewhere in Italy, and usually it is only Bonajuto that is sold beyond Modica. I’ve found it in markets in Palermo, and it wouldn’t surprise me to find it in airports or shops in the bigger tourist cities like Florence, Rome and Milan. (Venetians seem uninterested in chocolate, but maybe I just missed it.)