I would like to have a feature (maybe a setting in the general options) that removes tracks automatically from the playlist after they have been played.
Maybe keep an entry for one or two additional tracks and then remove them.
Are you referring to the Play Queue and not an actual playlist?
You can use the Auto queue feature for this by defining how many tracks that shall be maintained and retained.
More information can be found here:
Wouldn't it be possible to add an option beneath "Add from smart playlist" named "Only remove previous tracks" in the auto queue feature?
If this option is enabled, the "Automatically maintain at least xx upcoming tracks in the play queue" is disabled/removed and only "Automatically retain at most xx previous tracks in play queue" is used.
If we would put that option there you could not combine the "retain" feature with the other options, or do I misunderstand?
The motivation behind moving the "retain" option out of the auto enqueue feature entirely is that is can be used whether auto enqueue is active or not.
Which other options?
If I understood the request correct, it's just about removing previously played track - maybe not immediately but retain xx previous tracks.
That could perfectly be matched within the auto-queue feature.
But in the end, only D:Nero can tell.
I just think that that those options (automation within the queue) should stick in the same dialog and not be spread.