I’m trying to catch up on this suggestion. From the looks of it there’s quite some mix of different suggestions in this thread.
As for the original suggestion (OP)
This seems to have been implemented some time ago. You can search playlists and the playlists view/library can be sorted.
Therefore I consider the actual suggestion implemented!
As for a lot of the other topics.
I’ve been going through the thread… some of the posts discuss filtering/sorting inside a playlist. That’s obviously possible for smart playlists which inherit their order from their filter settings.
For “dumb”/classic playlists there’s other suggestions which already address this topic (incl. options to support a more extensive table view) – e.g. Feature Request: Playlist tabular view with sort-able/select-able/filter-able columns for showing metadata
Therefore I suggest to comment/vote/push those side-tracks in the respective suggestions in order to avoid distracting/dispersing votes.
As for discussions about individual missing sort options, I suggest to create follow-up suggestions. Otherwise those missing aspects will be drowned and won’t be noticed (even if keeping that thread open).
