Originally Posted by HarryT
It's a new engine. It only works with Kobo's own "KePub" format, not standard ePubs.
Indeed. I just tried loading a bunch of ePub3's onto my Glo and while they all loaded none of the new ePub3 features worked (R2L, MathML, fixed layout, etc.). Perhaps if I fiddle with the extension I can 'trick' it into thinking they're kepubs to trigger the new engine...