I personally think we should keep it to the original four ghosts. They’re the most important ones to the story of the saga, and the others (besides maybe Ahsoka) never learned the force ghost thingy. Plus, at this point in the film Leia’s body is still physically present.
That’s what I was thinking. Qui-Gon was just a voice, only able to physically appear in areas with lots of light side power. Mace never learned it.
I do appreciate the visual upgrades to some of the ghosts (namely Anakin with his hand out). I think those are definitely worth putting in.