Is there a setting/way to have the app close itself after a specific time when not in use? I know other apps like Musicolet have a setting where you can specify a time so that when the app has not been used for x minutes, it will automaticall shut down (and not run continously in background).
Settings like that are just snake oil. In easy words: as soon as you leave an app (and it’s currently not playing, updating, etc), it does not need battery.
What makes you think that AntennaPod runs in the background? If you mean the task switcher: It shows recent apps, not running apps. If you mean some kind of task manager: An app being shown in the task manager does not mean that it is actively running. Android works very differently from eg Windows.
I am experiencing massive battery drain with Antennapod. It is strange because this was not the case when I only had a couple of subscriptions. But I imported around 200 and now the battery drain is enormous, even though automatic updates and auto-download are disabled, and I only update and download 1-2/day. Even just listening to downloaded episodes now uses a ton of battery…