QuickDesigner: Ugly workaround for none-native kits

Steps to reproduce:

• have only a none-native Qt (e.g. Qt for iOS) configured
• create a Qt Quick Application using the kit with this Qt
• switch to Designer

Current result:

• Designer just complains about "The executable of the QML emulation layer (QML Puppet) may not be responding. Switching to another kit might help."
• Designer switches automatically back to Edit mode
• I have to configure and add a native kit for this project to be able to use Designer

Expected result:

• possibility of using Designer does not depend on the current selected/configured kit (I could live with having a limited support for non-native kits)

Note: Wasn't there something like a fallback puppet? Why not using this one?