Havent logged into crates in a few months and surprised to notice that the up/down arrows skip to the next or previous unplayed tracks. Sometimes i like listening to a track more than once, or comparing it with the other tracks in its release.
My suggestion: SHIFT+UP or SHIFT+DOWN skips to previous/next unplayed track. UP + DOWN (unmodified) increments by 1 in either direction regardless whether the next track has already been played or not.