There is no indication whether a song (track) is present in a playlist. This indication would be welcome in order to avoid duplication in playlists and would be an important piece of information. Roon did this very well in version 1.7 (curiously disappeared in version 1.8).
Do you remember how it was displayed in Roon back in the days?
Yes. Of course.
This information was placed just after the title of the track being listened to. If the title belonged to several playlists, they were displayed in a row, then on a line break if there was not enough space.