Just wanted to reply on what I’ve been testing.
Using Landscape tools
Tested out making a landscape while using a custom square brush to add depth to the scene. The problem is even when the brush is a perfect square landscape tools automatically add a little slant to the edges making every edge into a ramp. Is there a pure extrude tool in Unreal? Also, while painting textures like stone roads the painted textures end up mixing together creating a gray blob. This could be fixed with world aligned textures but now I know those are taxing. All in all it looks like landscape tools might need some tweaking.
Custom Level Editor Using "Editor Utility Widgets"
I was able to improve the processing speed by using a single blueprint with instances of the block within it rather than having multiple blueprints in world with the same static mesh in them. The new problem is that I now can’t change the material for every individual block to give variation. I think I could change the material by using hierarchical materials but I’m gonna have to do some research.