If it's solid at room temperature, it's not going to break down in a fermentor to provide significant character. This is why most people employ alcohol to dissolve similar hard chocolates to create tinctures/extracts to provide that character enhancement to the base beer.
fwiw, I soak chocolate nibs (basically dried solid fragments of fermented cocoa bean meat) in dark rum for a week or two (along with a couple of scraped, chopped and smushed vanilla beans) before adding the entire works to my double imperial chocolate stout. All of that is to get the cocoa character out of the "beans" and into the beer...
Cheers!