While it's convenient in propagating my shows that don't have previously downloaded shows and only keeping up with the new shows, it is limited in letting me also selectively add only specific earlier shows to that playlist from a podcast which say I have 100 downloaded episodes. I don't want all 100 episodes propagated into the playlist! And I don't want to only add the most recent ones either by utilizing the "add most recent". I want to add a much older episode and listen forward through the series.
Oh, I see - yeah, I can imagine the Podcasts app would be useless for that kind of playback. I hadn't considered that, even though I also subscribe to several podcasts in that way.
What I do with those sorts of podcasts (Stuff You Should Know, In Our Time ... the podcasts that to my mind are more like audiobooks in that I can listen to them years later): I don't even subscribe to them on the iOS device. I subscribe to and download those podcasts through iTunes on my computer (and do I sync podcasts between the different devices and my computer? Oh my god no!), and then change the Media Kind to Audiobooks, and after that manage and sync them as audiobooks. For example, limit the playlist to ten episodes, unplayed only, chosen by oldest or newest or whatever pleases me; whenever I sync, every couple of weeks, the list will repopulate.
Note that earlier this summer Apple moved audiobooks into the iBooks app, which was initially even more disastrous than you would have thought, but now it's manageable. You can't directly sync playlists from iTunes to the iBooks app, but you can use the iTunes playlists to determine what content is actually synced over.
I'm kind of amazed you've ever been able to listen to those sorts of podcasts through the iOS Podcasts app. The early versions of the separate app had me stop downloading podcasts to my iPhone at all for a year or two, and just download and manually sync them from my computer. It was only last year (I guess?) that I started using the Podcasts app at all.
Good luck. The days of looking forward to new updates seem to be a thing of the past - now it's more like "OK, so what will Apple change this time to make it even more difficult to do what I want to?"