Dear @vix
Updating to Qt 5.6 is probably not possible, because this version requires compiler features which are only available in VS2012 and later. This is the reason why only WEC2013 support is available. We are in contact with Qt anyway, so we can ask them whether they would be willing to adjust Qt5 to be supported on WinCE6 and 7.
We will investigate how much effort it is to update the documentation for using Qt 4.8.7. Actually we expect that there are only minor modifications. Did you face any particular difficulties when applying the Qt 4.8.4 tutorial to Qt 4.8.7?
Regards, Andy