Problems with Exclude Roads

Following the addition of the Exclude Roads option I’ve noticed no further
comments being made on this website so presumably this option is working
successfully for other users, but I’m wondering what I’ve done wrong as I am
encountered the following problems:-

  1. While traffic has been successfully removed from most roads, two short remnants remain, which have traffic on them.
  2. None of the translucent OSM road surfaces have been removed. Though I have noticed that following the most recent update (to version 1.21.18.0) these are now significantly less noticeable, but why they have to exist outside the developers mode is not clear. What purpose do the translucent OSM road surfaces serve?
  3. On those sections of road where the traffic has been successfully excluded visually, bizarrely you can still hear it!

I’ve tried adding additional polygons with Exclude Roads option over the
affected areas, but these have made no difference. Has anyone any further
ideas please?