That’d be a lot of work but it has a nice look to it. You could even have it when Vader eventually tosses Palpatine down the reactor shaft, it is actually could have more lava at the bottom. When he falls in though, you could still have it where he explodes into that blue spirit energy or whatever.
If you were to expand on this, you could even have Luke and Vader’s conversation on the landing platform catwalk take place on Coruscant, and rotoscope that background as well. It would be cool to spend at least one scene on the planet surface that way. Maybe it is right before they take the elevator down to deep beneath the planet.