A great feature to smoothen transitions between songs would be a “mix-in” mark, which would take place AFTER the cue-in.
The idea is to mix the very soft beginnings of certain songs (like waves, for example) into the end of the previous element.
The “start next” of the previous element arrives at the “mix-in” point of the song, but the very beginning of the song has already been played during the end of the previous element.
The difference is that the “fade in” (and of course the song) starts at the the “start next” of the previous element.
With “mix-in”, the song has already been started so that the “mix-in” matches the “start next” of the previous element.
Not currently possible to do this automatically (and reliably) with the way the current playout engine works, as one item/player cannot have influence on the other.