Currently UE4 editor mostly not usable for serious development on most laptops because laptops has low-end GPUs like intel 4000 etc, and it can’t be used on virtual machines like VMware Fusion or Parallels because VMs currently only simulate DirectX 9x - But lots of indie and small game developers teams is using laptops as main hardware for development (especially for mobile games projects) (VMs also used for some reasons for instance use VS for iOS development or deal with Win related things with projects which is focused on mobiles but also allow of using on desktops for users) therefore it’s really huge issue for UE4 (for example Unity3D works without any performances issues on intel 4000 and even in VMs ). Because of this I think that solution for this problem is can be a implementation of separate rendering engine for editor, which will based on DirectX 9 or OpenGL and allow doing most things on low end GPUs with ability to use actual rendering engine for preview advanced effects.