Okay, I have no idea if this is possible but I figured it's worth trying I am working on a concept using the geometry nodes morphing effect seen in my example below.
Now, what I am trying to achieve is to have the morphing object to use to two source object's UV map. So when the object is in sphere form it has the UV Map of the Sphere, and when I morph it into a Cube it switches to the UV Map of the cube.
To offer a better example of what I am talking about, here is a basic example of the texture I would use on the morphing object. I don't know how to make the UVs work here, beyond obviously storing them as attributes (I don't know if it could store it as a single UV that morphs with the mesh, or if it should be stored as two separate UVs, one for the Sphere one for the Cube) with a second/third attribute or a driver controlling the Mix factor.
And to be clear the end idea isn't a cube and a Sphere, the idea would be clothing on a character that can morph into different forms (think how Dr Strange's clothes morph from the suit he's in at the wedding to his Sorceror Robes in Multiverse of Madness) with the different forms featuring texture painted details, necessitating the UVs.