I decided to give up on it. Looking through the docs, they recommend that due to “reasons,” it should be restarted at least daily, preferably hourly. I don’t know if they have a memory leak or some other issue, but that was reason enough for me not to use it.
I installed TubeArchivist, and it suits my needs much better. Not only do I get an archive of my favorite channels, but when a new video is released, it gets automatically downloaded to my NAS and I can play it locally without worrying about buffering on my painfully slow internet connection.