Yes, this seems like a glaringly obvious useful feature, and I can’t figure out how to do it. When I import real terrain, and it comes in with blockiness at the contours, it requires lots of tedious smoothing with the largest brush.
I tried to follow some ideas about using Gaussian blur, and increasing the colour depth on the heightmap png file, but invariably, this involves introducing noise which then results in an unwalkable landscape.
Still looking for an answer e.g. in blueprint!