I'm dividing my ground mesh into several smaller meshes for performance. Is it better to do one StaticBody with many MeshInstances and colliders as children, or have several StaticBody nodes with only one MeshInstance and collider as children? Or does this not matter?
One StaticBody with many MeshInstances or many StaticBodys with one MeshInstance (each)?
When I was working on voxel terrain generation in Godot, I found that performance was better with one larger collision shape than it was with many smaller ones. In my case, I found a sweet spot between large collision shapes and performant voxel processing in chunks, so I could modify the world but keep the collision shapes fairly large.
Though I would highly recommend you test to know what would work best for your project if possible. In my case most of my collision shapes were close together, which may have a difference and may not be applicable in your case depending on your project.