Is this repeating radio burst trapped inside a young supernova remnant?

FRB 190520B is a fast radio burst that repeats from a dense, changing environment. Researchers fit observations of how the radio waves spread and delay through the burst's surroundings to a model of an expanding supernova remnant. Only six scenarios match the data—all pointing to a very young remnant with a thick ejecta shell, but the scattering pattern hints at hidden complexity inside.