Does CoreText have any facility for selecting a SmallCaps variant of a font, or for synthesizing small caps if the font doesn't have that feature? I can't find anything in the CoreText documentation that talks about small caps, though there are facilities for dealing with font variations/features. Has anyone done anything similar to this?
It's generally easiest to use CTFontDescriptorCreateCopyWithFeature. As you mentioned in your own answer, this will only work for fonts that actually implement the feature you are requesting.