Would it be possible to integrate the ability to define custom sort orders with conditions for playlists and collection, which can be applied where it is possible? E.g., I want to sort my playlist by artist and then year of the album, and, if no year is available, by album title. Then this should be selectable through a menu. Or: There are the predefined sort criteria in the collection, like Genre/Artist/Album, but I would like to be able to quickly switch to an order like Genre/Artist, or Album, if it's a sampler/Album,  if not.
Secondly, this should also be possible with filters, so that, in the context menu of a collection entry, there is a submenu with all the saved filters listed, like: Load all tracks from genre XY that match filter YZ. Or, apply custom filters to the current playlist.
And please add "Date added to collection" to the filter criteria!