Now that I think of it it would be nice if we could figure out some solution(s) to Mustafar. I do have a couple ideas in mind.
I’ve seen some other people post tests were they added more establishing shots culled from other sources. I think that’s probably your best bet. There is a canon reason why Mustafar looks the way it does in this movie but for someone only tuned into the films it’s a bit confusing.
Basically I think there’s the ‘lean it to not looking like Mustafar’ approach, and the ‘try to make it obviously Mustafar’ approach.
For the first, I’ve found a decent shot that matches what we see, although it’d be great to add a couple TIE fighters and/or some distant laser blasts.
For the second, there’s a shot from Rogue One that’d work, but you’d have to swap out Krennic’s shuttle with some TIEs, then I think it’d also be helpful to try to make the footage of Kylo seem more like Mustafar as well.
Either way involves VFX unfortunately.