hi there! 
this is kinda much of an interesting stuff, i still dont own such a notebook, just planning it for the not-so-near future, but that numpad-like behaviour is like the [fn] key is playing an important role in the issue, so you can maybe experiment with it.
i can totally feel the pain, however i only had strange letters in place of őűŐŰ (hungarian stuff) in my x11 based gui toolkit (tekui - its a pretty great tool anyhow, but its not flawless; http://tekui.neoscientists.org/screenshots.html ) and the best i could do so far is monkeypatching it inside tekui like override some keycodes around its message processing instead of fixing its driver, and as i had some smaller or bigger researches around, i know that you can remap keys in x11 as a workaround, and that will serve u well in doing ur business til theres no better solution…
bests!