I came across
Greg, which looked incredibly tempting, and which, like newsboat/podboat, was optimized for the download-the-audio-files-from-the-terminal-first workflow that a lot of the people who responded liked.
But then I thought, hey, why should I download the episodes first? All my players can play network streams, and I have an Internet connection that's reliable enough to do that.
My decision? I ended up buying PocketCasts.