@mandy314: I can't speak for Amazon's FT implementation, since I pretty much got rid of it on every device except my K4, but I'm pretty sure the KF8 reader (if not the legacy M7 one too) should handle kerning (since it's basically FT+FC+Pango).
That said, I'll check that more throughly tomorrow, because the whole font rendering/script layout stack of the Kindle sometimes does crazy things for no apparent reason

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EDIT: Hmm, I might have been dreaming that. Or remembering old tests w/ a different ft build/font, because, yup, no kerning w/ my current setup. Will check in detail tomorrow.