This situations avoids any outright inconsistency, as in the Grandfather paradox, and so is broadly logically possible- I wonder how the analysis differs under an A-series theory of time vs. a B-series theory of time? I’m not well-versed enough in the metaphysics of time, but it seems possible that some of the physical/causal objections could be mitigated under the B-series?

But the point the @E-isme is trying to make is that, this creates an entirely new timeline where Einstein was presented with these ideas instead of coming up with them. He is still the original creator, it’s just in a different timeline now.

In this example Einstein did not write his work. That’s the whole point. In this example he never would have come up with a theory of relativity without the time traveler telling him about it.