Sounds like a solid job! I keep the actors steady by laying out the exact blocking on the set—those little white chalk marks on the floor and a clear line of sight for the camera. I’d also run through the scene a few times, let the crew set up the lights and lenses, and make sure the camera crew has a solid shot list. If everyone knows their exact spot and cue, the actors can focus on the performance instead of fretting about the walls. Easy peasy!