The 2D View of the Fixture Monitor is a big leap forward, great!
It works fine, only issue I experienced is adding fixtures to the 2D View does not change the "dirty flag" of the project, which means you could close the project and QLC+ does not warn you, that you will loose this changes in the 2D View.
To reproduce: Open a saved project, only add fixtures to the 2D View, close the project. You won't get any warning, but on re-opening the project you'll notice the changes in the 2D View were not saved.
Environment:
QLC+ 4.7.0
Ubuntu 12.04.4
Q Light Controller+
Official forums of the QLC+ project