the only thing i can think of is that youre not going to get the efficiency or the starches or the flavor from the roasted grains like you would if you introduced them to the grist at dough-in. the astringent flavors can be removed by modifying your roasted grain content, and using the proper yeast and fermentation process. you can try that method, but i think your beer will turn out,......uh.....different.
ill keep my money, guns, freedom, and religion......you can keep the change.
You like fishsticks, what are you, a gay fish?