Should Batman's cape be CGI? Snyder proved with 300 and MOS you can do far more visually with a cape if it's cgi. And since the cape would likely be black, or a very dark blue (if they choose to revere the comics to that extent) the CG shouldn't be too conspicuous.
Alan Moore on comics:
They've lost a lot of their original innocence, and they can't get that back. And, they're stuck, it seems, in this kind of depressive ghetto of grimness and psychosis. I'm not too proud of being the author of that regrettable trend.