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.
They should carry a foldable chair so they can sit down white watching at the screen for the on field review.
And have a bag of popcorn hanging around the neck