I’ve seen a few Epic engineers say , it defeats the point of using Splat (RGBA) / weightmaps to cover the terrain. You may manually paint roads etc. and detail paint, but never in a sandbox setup would you ever manually paint the whole terrain. Especially when it’s a larger game, imagine trying to replicate a world machine splat by hand over a 30KM2 stretch of terrain? The documentation doesn’t cover the way that works, whether it’s the correct way or not.
Landscape Layer Weight nodes and .RAW splat weightmaps are the only safe way to go, which is fine it works. But there are still limitations there, because you need a Gaussian blur to blend the weightmaps, due to your resolution dependant vertex paint setup. Which is by far not the best way of doing things…
On the list of problems though, a bit of blocky paint isn’t exactly high.