Did someone try out the Granite SDK (huge texture streaming) for Unity? Seems promising.
http://graphinesoftware.com/products/granite_for_unity
This upcoming game uses their SDK as well, so if we can use this tech in Unity, that will be awesome.
Actually, it looks like Amplify 2 is better because it supports PBR:
I am getting an error that says it won’t work on 2017.2.