This "trick" creates a converter prop. If you have the same model with two different UV sets, the generated prop will convert textures from one UV set to the other. It's not a shader nor a morph. It's a way to convert textures.

You need the same geometry, though. You could not use it to convert from V4 to Pauline, because the geometry is different.

A ship in port is safe; but that is not what ships are built for.
Sail out to sea and do new things.
-"Amazing Grace" Hopper

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