I’ve looked at that video here: - YouTube
That solution has so many downsides that can be an issue for what you want to accomplish, which you still haven’t made clear what your plan is
So to start–it has collision but doesn’t have spherical gravity, which is a problem in itself. Without a physics system designed for that then many gameplay features of UE4 won’t work, not just physics, but AI and even the basic way that things like Blueprints will use things.
It uses meshes, so it can’t take advantage of many of the features of the engine, like terrain. I’m not even sure level streaming will work properly with a sphere broken into pieces.
The landscape is low-detail without all that many props. To add more detail and props you then get the issue of disc space, even storing the position of objects can add up to a lot. It also doesn’t have much variety, which will add more to the complexity and the amount of work. Many other visual effects aren’t good, you could spend a lot of time trying to make a sky that looks good on a spherical map.
So to summarize, the visual quality is poor and the method means that you can’t do much gameplay. If your goal would have a higher quality level, and any more interaction than just flying around it then you’d have to pretty much tear apart the engine to make it work. That’s why people make their own engines to do this type of thing and then spend years working on them. Take for example No Man’s Sky, their solution is a custom engine and years of work, the graphics aren’t super complex which they avoid by having it heavily stylized.