This is a re-run of my large conjoined thread - https://rocket.unrealengine.com/questions/1841/feedback-my-next-round-of-contenteditor-feedbac- broken up in different threads as per request of Alexander.
The sprite icons in UE4 render behind translucent meshes, thus making them stand out less. Following screenshot shows light and reflection actors positioned well in front of a translucent fog plane. However the fog plane is rendering on top of the icons, making them blend in. This makes the editor less readable.
https://rocket.unrealengine.com/storage/temp/10165-iconsbehind.jpg