Today, even though "real tracks N/A" shows up on every single real track style, once I load a style into the plugin, the real tracks are there. Then, an hour later, when I decide to try a different style, I load it up an all the real tracks are N/A. Rebuilding the style picker cured it. Apparently, rebuilding the style picker virtually every time one uses the AU plugin on Mac is just part of the workflow. And today, I had drums! I didn't have them yesterday.