Enable Design Studio use on all Qt supported hosts in combination with Qt DC embedded use cases. Qt DC does not support MacOS (or supports it poorly) which is ok if designer-developer workflow can be supported accross different host operating systems. Designers should be able to use all Qt DC (and QSR) features (E.g. virtual keyboard) for QML (and play with them locally), and then have developer to pick the file and work on the rest of the application.
petref you promised to draft this to next level, I'll leave some notes on comments and added some links for more information.