Auto-downloads work wonderfully here and can even be set per-podcast which is such a nice feature.
Not saying this to denigrate your experience but to perhaps soften the 'is horrific' notion into somewhat more of a 'does not work for you' one.
Otherwise, I suppose Pocket Casts is also open source nowadays - or has always been and I did not notice? But that was a reasonably good alternative for me as well before I switched to AntennaPod.
I have similar issues. Guess it's because I listen to vary long podcasts that I often don't finish, because there's a newer episode already. Because of that old episodes will be considered unfinished and block new ones from getting downloaded. Maybe if there download limit is set to e.g. 20 Antenna Pod should delete the oldest episode of the 20 downloaded and download the newest one when it gets released
I use it daily and it's great.
It has really granular controls and I only download some podcasts and even those I can cancel the auto download if it has a word reference I don't want.
My only complaint is the syncing between devices which admittedly is not great.
That is a little of how I use it too - I have all podcasts set to download automatically globally (set it up to 25 episodes at the same time) and put them in my queue so I always have exactly 25 episodes to listen to in any order there each day.
Then there are 2 daily podcasts that I do not let automatically download (but automatically refresh, and I love that the app delineates between the two), however one regularly produces longer episodes including a lot of the shorter ones that I do let it automatically download. Huh, I never realized how advanced the setup actually is. Though I do remember the actual 'setting up' being relatively painless after getting to grips with the global/per-podcast difference.
Also, fwiw I have the synchronization set up using one of the self-hosted options instead of the default gpodder service - which is often down intermittently - and it works well enough, even if a bit slow every now and again.
Also sometimes it just literally does nothing. Push the play button and nothing at all happens.
That's a bug with the notification/lockscreen widget AFAICT. Pressing play on the main player window should work. This is the most serious bug I've found. It's quite a promising player otherwise.
I'm happy to know that Pocketcasts is OS now, that was my player of choice before trying to jump to Antennapod.