With Stratechery, once you get to the website with the magic link, I can then copy the authenticated podcast RSS feed to Overcast and the authenticated RSS feed for the articles to NetNewsWire.
Those subscriptions are then synced to Overcast and NNW on my iPad and Mac via iCloud.
Each podcast RSS link is personalized and you go to the show notes page and click on the link to Manage your account. It will take you to the website using the embedded browser where you can manage your subscription and get access to the various feeds.
Speaking of Overcast, even though its doesn’t create a username and password by default, you can create one. But it’s only to access the web version of Overcast.