Dark chocolate is a fully cooked, fully developed ingredient in its own right, robust and forgiving. Remember that it has been roasted and then heated again to fairly high temperatures in the conche, and that it’s a relatively simple physical mixture of cocoa and sugar particles in fat. The most that a cook needs to do to it is melt it to perhaps 120°F/ 50°C, but it can be heated to 200°F/93°C and then some without suffering disastrous effects. It won’t separate, and it won’t burn unless it’s left over direct stovetop heat or in a microwave oven without stirring. It can be melted and solidified repeatedly if necessary.