Unreal Engine should add support for Dualshock 4 controllers, and all of it’s features like the Gyroscope and the touchpad (Without the need of third party drivers) out of the box using a plugin, and include functions for Blueprints and C++ that allows changing the button prompts based on the connected controller in use.
I would also like to suggest the idea of a Toon Shader model that works simillarly to the default toon shader found in Maya and Blender, without needing a custom engine branch, and without experimental edits through the material editor that end up looking a bit crummy.
Seeing an option for adaptive resolutions based on desired framerate in the scalability settings would also be great.