Beware of the Reicast cores, their CHD support it's outdated. They don't support the latest version (v5). If you grabbed a recent software list or compressed your games to CHD in the last three years, chances are they won't work with Reicast.
Redream can read CHDs v5 but that core its very glitchy, not recommended. I personally use Demul for Dreamcast related stuff, great compatibility and CHD support.
UPDATE march 2019: The reicast core now fully supports CHD for a while now, so if you update your reicast core to the latest version, you should be able to load any CHD. And it should support multi disc games too.