Please don't consider using this at least until they make their own demo accessible to non mouse users (I raised the same complaint the last time this was posted, no change).
Honestly, I wouldn't hold your breath. You're probably so far on the fringe that it's not worth their time to fix it for you. They're demo works fine on my phone (Opera Mobile browser), the only mouseless interface I use.
I'm all for keyboard navigation, but I'm not at the point of boycotting if somebody doesn't support keyboard-only interaction.
Well, the goal of using an already-made UI library is to not have to think about these issues. I.e. if you're paying a couple hundred dollars for a library, you assume it has been well tested. (And, if keyboard shortcuts don't work, it's obvious that it wasn't tested enough.)
Combo boxes don't work at all on the iPad (or, presumably, iPhone). Long ones such as in the welcome demo page select items instead of scrolling on drag. Short ones on the combo box page close as soon as they open.
The landing page made a big deal out of supporting touch devices and being a HTML5 app framework; I wouldn't build anything on a framework whose own demos don't work on the most popular touch devices in the world.
Touch scrolling is not enabled for mobile devices since there is native scrolling already (with two fingers in iOS below 5 and with one in iOS5). Custom scrolling can be additionally enabled.
I'm all for keyboard navigation, but I'm not at the point of boycotting if somebody doesn't support keyboard-only interaction.