The author could make the process of adding a YouTube RSS address easier. For example, www.youtube.com could be added as a search option alongside itunes.apple.com and api.ffyd.de.
Add Podcast | Add Podcast by RSS address
https://www.youtube.com/feeds/videos.xml?channel_id=UCwWhs_6...
For me it's faster and more flexible to automate all RSS and download tasks on the commandline using custom utilities. Then upload the MP3 files to a folder on the phone so can listen offline using the app.
Add Podcast | Add local folder
If going to be online then just use direct URLs to MP3s. More flexible.
It's the best full-featured F-droid app in my opinion. I might even rank it second after NewPipe as a top-tier "killer app" on F-Droid.
But it does play the audio.
It's even available on F-Droid.