@warner Apologies for the delay in my response...

Interesting point regarding Spotify! My reading up suggested that the company did ingest MP3s, but if they aren't or have changed something since then, then great! 👍

I distribute Really Specific Stories with Fireside and really enjoy the service.

Yes, I think that Micro.blog is a great platform for microcasts. I'm not sure that your proposed MP3 (song) file example would be an issue: if you were to delete the file and replace it with a new one, then other directories should eventually update according to what you've changed.

Micro.blog is perhaps the best place to start a podcast because it is affordable, easy, aligns with your existing blog and gives you a reasonably safe space to experiment. If you want more analytics and customisation, which frankly are less necessary than you may think, then you can explore other services. My decision to use Fireside for my PhD podcast was because I wanted a separate space and was impressed with the service after using it with @HemisphericViews.