How can it compete with itself?

You would have to own V4 and load it into the scene before applying a weight mapped injection pose. Does that not enhance the perceived value of V4? I fail to see how it could detract.

Consider a remapped V4. One has to provide the new UV data in a form that can be "injected" into the original. One must similarly own the original version before one can use the revised version.

I've not heard any argument that this violates any EULA so why now with weight maps?

Yes I probably could answer my own question but that would mean going back to the beginning, the start of it all and I do not propose to make that exodus.