The thing is, Kindle
can show old-style figures (by drawing glyphs from the .smcp section of the font, when forced with
font-variant:small-caps). If the font supports it—such as the one included with the epub by the publisher—it seems very unusual to add support to some OpenType features in the Kindle, and not others.
As a side note, I’m not sure which OpenType features recent Kindles currently support, besides small caps. Stylistic sets? Extended ligatures? Diagonal fractions?
The list in the Adobe article is wonderful, but it doesn’t specify cross-platform compatibility. Some websites (
such as this one) mention the small-caps feature as an exclusive EPUB3 feature, and not on Kindles, which is wrong.
It’s not very clear, and their Kindle Previewer software doesn’t offer the slightest hint regarding this. Is there any clear compatibility article somewhere that I missed?