I can imagine why you got that refund-request.
1: The Pack is called “Infinite affordable Landscapes” (there is nothing infinite, because the Landscapes are a square - this is just how it works, but the Pack-Name is “wrong” - at least from my point of view. Even if you add one Landscape a Month, there is nothing “inifnite” - you will end up with 24 landscapes for the 2 years you wrote in the description.)
2: The “Dust” he shows in his video really looks “weird” i think, but that should not be a problem if he can deactivate it.
None of them, especially if there is PDF-Documentation about that stuff.
And… that “Asset Guidelines” they require… this might sound stupid for us, but not for People who do not know that a not connected “metallic” node means “0”.
You know… People download UE4, buy stuff, dont know how to use it, and then they are coming around with questions like: “why can’t i add metallic to material XY?” or “i want a refund!!!111 material not working!!!11”