| Is there any particular reason that you've enabled J6X0TP_WSMOUSE_EXCLUSIVE
 | and uncommented J6X0TP_*_ICON_KEYSYM?

No reason.. I merely tried to those options last day.

 | I think Xhpc should be changed to open /dev/wskbd mux - then both the
 | primary keyboard, the hard-icons mini keyboard and the external
 | keyboard can all be used simultaneously in X.

I'll investigate later.