I've used mine at ATA shoots and haven't hit anybody yet.
Some folks don't like empties dropping even remotely close to them. But as long as they're not hit don't worry.
My SS tosses hulls inbetween me and the next shooter. If they don't like that, tough.
If you're concerned put a rubberband on the gun just forward of the bolt handle. That'll catch them well enough but it can be a little time consuming to dig them out during a tournament. Best long lasting RB's are the thick, blue ones that celery comes wrapped in.
Nobody makes a good shell catcher for the SS - yet.