Audiologist "doesn't do" REM?

Did you try Naida Lumity e.g. 90 SP? I know there is no Naida Infinio lineup yet (will be soon), but you could at least check if it would provide better audibility in quiet with soft voices.

If you don’t get the basics, like audibility in quiet, there is a risk of obtaining little to no benefit from “bells and whistles” like StereoZoom 2.0 or Spheric Speech Clarity.

See: