Hey ho,
still work in progress, tutorial is coming when I finaly find the time,…
but here it is…: Unreal Engine 4.26 Layered Autolandscape Material Preview and Quixel Surfaces - YouTube
Automatic,… with paintable layers, easy addition of more material layers… everything exchangeable on the mat instance… texture bombing inside,… distance controlls… a lot of blending…, proper height-blending within the automat layer,… and for the paintable layers aswell… full displacement and tessellation support… oh and nothing for “real” realtime so far 
(but rendering out is fine 
… 5400 frames in around 2 hours, …)
All material maps from Quixel (great stuff!)
Cheers
P.