I presently work with pretty basic tools, I’m not that experienced with digital alteration as of yet, it’s a great idea though, I did sort of try it out raw, had some timing issues.
I used adobe after effects for more detailed fx. Still would be hard to repace background because of the glow of kylos saber.
But yea good to do a raw test to see if it even works. Im just going by memory if itd work but seems like you just looked at footage and like you said doesnt work.