The standardization of CSS class names for controlling the appearance of teacher - specific content is under consideration for a future version of this profile.
On the other hand, the styling for the drop cap itself seems to have been given a consistent classname throughout, so if I wanted to make the drop caps bigger or turn them red, I could do that by changing a single CSS rule.
For ebook - friendly consistency across typesetting and ebook production, it's important that you use exactly the same terms for intended book features, InDesign style names and HTML / CSSclasses.
During Media Overlays playback, Reading Systems with a CSS Viewport should add the classnames given by the metadata properties active - class and playback - active - class to the appropriate elements in the EPUB Content Document.