Imo VAR should only exist in a technical capacity to prepare footage to transfer onto a ref’s portable Fold 5 or something. Samsung could sponsor it even!
The decisions should all be made by the ref on pitch and this would massively improve the speed of play during VAR. There’s no reason they should have to walk off pitch.
Some stadiums have very large screens in the ground, I think this would be a simpler idea to implement with the benefit of the crowd seeing too and players wouldn’t naturally crowd the ref just by trying to see the images.