I’m not sure if I like force ghosts being able to interact in the physical world at all. They COULD potentially wield lightsabers etc but it is clear they can only appear in moments of need as the Force wills (as Ben says to Luke before he rushes off to confront Vader, “I cannot interfere”) so maybe it’s no problem.
I suppose Qui-gon appearing to confront Vader and let Obi-wan escape would be a nice moment in many respects but it would all depend on execution.
Force Ghosts are another idea that I used to like but were ruined by terrible ideas/writing (Yoda in TLJ).
Would have rather just had Obi-wan continue as a disembodied voice like in SW77.
Honestly, Star Wars is such a corporate product now. I am very close to requesting the mods ban my account here.