Material Switcher
Blender presently has no way to animate (keyframe) material changes. The only workaround is copying everything into a single material and using mix nodes.
Well that ends here...
Material Switcher is a simple addon that lets you keyframe which material is active (with 4 available slots). Apply this tool via the modifier panel.
Toggle between 4 customizable material slots.
Keyframe just like you normally would.
This works with any object and any set of materials.
Installation works like any other addon. In Blender 4.3 (or newer) just drag the .zip right into the program and hit accept. You will now have Material Switcher in the modifier menu.