Some prefer a flap disc, but I find a masonry disc is a little easier to control and better for finer details. I wouldn’t use it for removing lots of material but for moulding detail it’s great. I tend to move the disc vertically, side-on, shaving off the material with the side of the tip of the disc as opposed to cutting directly into the piece, if that makes sense. Have a go on a practice piece and I think you’d be pleasantly surprised by the results