Thinking back to the “Saving the Reveal” proposal - would it also work if a concealed face (via darkening) and recolored suit Vader still slaughtered the Separatist leaders as done in the movie? Changing the lightsaber’s color to red would help this, as would cutting the shots of Anakin and R2 leaving the ship on Mustafar. It resolves a loose end, while also being a good dramatic beat before Yoda vs. Palpatine.

I’d keep the references to “Lord Vader” in the scenes, which would work well for furthering the idea that this new “Vader” (who may be the old Vader, as we never see his face) is a/still is a serious threat.