I have been owning various laptops for 3d works… and honestly when it come to UE4, you just need to make sure you have at least Nvidia 860/970, RAM >= 16GB and yes, SDD is a must. Otherwise the level loading will be unbearably slow. My main gripe about laptop is not performance - it is the Nvidia Optimus that kills it. I don’ know about other laptop, but both ASUS ROG and Lenovo laptops will switch to Intel graphics card when hooked to external monitor or HMD.