Is it worth migrating from Unity?

I have a project in Unity and I am very frustrated with Unity’s poor terrain system. I am considering migrating my project to UE4 but I am not sure if it is worth the effort to migrate and learn a new engine.

What would really help me decide is if someone with experience in UE4 could simply answer a “Yes, UE4 can do this natively out of the box” or “Possibly, but there is a catch…” or “No, there is no way UE4 can do this”.

  • Does UE4 allow “painting” any custom 3D models on a terrain with LOD?
  • Can I restrict where UE4 is allowed to “paint” 3D objects?
  • Does UE4 have a way to automatically generate imposters (by “imposters” I mean a billboard/sprite that updates as the camera move around it to simulate a different viewing angle of a 3D object like the Doom or Duke Nukem 3D engine) for LOD?
  • Does UE4 require separate texture files for 3D objects or can I combine it for performance reasons?
  • Can UE4 indicate on which terrain material a player currently stands and adjust the properties according to it e.g. sound, movement speed, etc.
  • Can I make (or fake) caves/holes in terrains in UE4?
  • How many different textures can I paint on an UE4 terrain before an additional graphics pass is required?
  • Does UE4 scale shaders based on a runtime set graphics setting. In other words, say a graphics card support a certain shader, but it too slow to render it and the user set it to a lower setting, can I switch to an alternative shader in runtime?
  • It is very easy and quick to test Oculus/Samsung GearVR mobile apps on a physical device using Unity. Is the same true for UE4?
  • Unity has the ability to specify export settings per platform, e.g. lower resolution texture for mobile devices, more constraint level-of-detail (LOD) groups, etc. Is this also possible with UE4?
  • Unity allows me to use my own custom network protocol. Is this also possible with UE4?
  • Unity allow multi-threaded apps. Is this also possible with UE4 specifically on mobile devices?
  • Will the base UE4 increase the download size of my app dramatically? I think Unity’s base size without any assets was about 15 MB (if I am not mistaken).
  • Does UE4 support bluetooth controllers on mobile devices natively?