For long, I thought they had become crazy. Then digging in the app, I found how to get it and it is in fact brilliant ... though well hidden and not well documented: you can customize multiple lists with selected podcasts which automatically get updated and can be called from the App icon using 3D touch.
Go the Podcast 'Library' page.
Click the 'Edit' button at top right
Create a new station for a given topic for instance
Once it is created, from the main 'Library' page, select the station
Click the 'Edit' button a top right
Click 'Settings'
Click 'Choose Podcasts...' to select those you want in that specific station
And also tune it the way you want : grouping, order...
Using 3D Touch on the App Icon, you'll find the Station and ... ta daaaa ... you can start playing it in a single touch :-)