Hi Greg,
Having been on several charters with 734 at the WMSR, there are some really nice downgrade shots. All it takes is an engineer willing to make a brake set and then work against it for the runby. I have photos with Mike Manwiller running where you can mix upgrade and downgrade shots and nobody can tell the difference.
As far as regular operation is concerned, not turning the loco should not be a big deal for the tourists but it does mean the railroad will need two crews for each trip.
Michael Allen