Idk how this was done, but I gotta say it looks like the best of both worlds when it comes to the force Ghost issue. This one is obviously a bit over done, he looks like 90 rather than 45 (also wow why did they have Sebastian Shaw playing him, I know that the prequels we got were very different to how they were imagined based on what we hear and see in the OG trilogy but still, he was even older than Alec Guinness) but toned down a bit I think this would work as both Anakin being the man how died on the DSII and link back to the prequels as Shaw just doesn’t resemble him at all.
https://youtu.be/z-oL4rEjcfQ?t=12