I have to ask the same question about the sea salt - crispy flake says a little about the texture but nothing about the saltiness and other flavors that might be in the salt.
There are hundreds of different kinds of dark chocolate and many, many different flavors and texture of salt to consider.
Your challenge, I think, is to balance the saltiness of the salt with the chocolates you are using. Some chocolates can "stand up" to more salt, some chocolates can't, and need less salt. I would first start experimenting with a very limited number of chocolates and then play with the amounts of salt being used and how the salt is used (sprinkled on the surface, mixed in).
One thing to consider is that salt can reduce the sensation of bitterness. You may find that more bitter chocolates can take more salt, and that when the bitterness is reduced, that other flavors will come out.