I'm glad newish android versions have a "allow sound from multiple sources" option, now nothing can stop anything I'm listening to but myself.
Before this only Podcast Addict had an option to ignore media pause requests from other apps.
This worked for me, thanks! You don't need to be rooted, but you do need to change some developer options to get Shizuka working. Then disable the "Audio focus" permission in App Ops on one or both apps.
Shit like this is why I'm afraid to move away from Samsung. So many little QoL things and I have no idea if some are stock. Usually only find out once I see them listed as a new android feature.