I think something like a rod that isn't attached to the handle but would float over it and could be used to pull on it could work. A hole in the rear of the catcher and a catch of some kind inside to hold it until needed and out of the way of the handle and discharging brass.
Discussion
As I think about it more could be easier to have hole in the front with a spring that pushes straight back. From the rear has more chance of impacting the brass flow path
Yeah, a captive rod with spring that keeps the pressure on the rod forwards of the travel of the handle but can be pushed back to move the handle. It would keep it out of the way for sure. Just need the rod long and strong enough to hit the full travel of the handle.