First of all; Sorry for the late answer, I never got the notification (or missed it) that you wrote again so I didn’t notice.
Thank you so much for informing me about this though!
Back when UE4 was released the old UDK way of doing it didn’t work (If I remember correctly the Tex2dGrad string didn’t work) and I never noticed that they had changed anything that would make it work now.
This will make it a lot easier to build more advanced landscape materials again!
Thanks again Mordachai!