I have done the poured/drizzled ganache on a cake that has been iced in Buttercream Dream, but I am wondering if it can be done with SMBC. I know that you don't pour the ganache when it's warm, but will it "melt" the SMBC or break it down in some way?

I've seen it done before. Maybe refrigerating the cake before drizzling it? That way the icing is firmer?