I couldn't see in the article if these stars go behind the black hole in their orbit relative to us. Or how close their leeward approach is. Such an event could add greatly too to what can be gleaned about space and time distortion.
A very interesting article, Glen. I wonder how far away from the black hole these stars are? Would have been nice to get some stat's such as the eccentricity, and some maximum and minimum approaches. And the type of stars they are and their velocities around the black hole.
I'll put the geek back in the bottle now,