A commonly requested feature in the old version of the bot was the ability to delete old messages as soon as new ones get posted. This can now be accomplished by enabling the Delete Old Messages setting using the /settings set boolean command.
Please note that this will not work for messages that have already been sent, so if you want the one-post-per-channel experience, make sure to delete the old messages! A good way to do so is utilizing purge commands added by a range of moderation bots, though you can always just delete and re-create the channel for a hassle-free experience.
Auto-deletion of Free Roam Events is a bit more complicated and will be added in a future update. As soon as you enable the setting, they will get tracked as well, so they'll be deleted as soon as that portion is ready.