I don't have a 14 Pro, however I imagine the battery drain would be negligible if you used a completely black background with minimal widgets. That way, you could see the time/notifications and still have the benefit of the AOD without the battery drain.
Having a wallpaper on your lockscreen with an AOD is a complete waste of power. It should show the minimum amount of information required.
Having a wallpaper on your lockscreen with an AOD is a complete waste of power. It should show the minimum amount of information required.