Overview
Material Split View is a Unity editor extension to preview the material with the split view.
You can easily compare two materials in split view with Material Split View. It is useful to compare the material with different settings or the material with different shaders, re-configure the material with different shaders, and so on.
Why Material Split View?
You might think "Why don't we just lock the Inspector?". However, this has problems such as having to navigate back and forth to Unity Project View and forgetting to lock/unlock it. There is this extension to avoid such annoying things.