Wow! It is a tad bit expensive, but that material function does fix a lot of the distortions with the simple method, and works great! Unfortunately, seams are still a problem, sometimes even causing the lava to flow in opposite directions.
What I’m hoping for is to find a method that works for both landscape and static meshes that can then be combined for interesting designs without requiring specific assets to each mesh while allowing meshes to be scaled and rotated. I’ll see if I can build something nice with this setup.