Found similar thing other day [0] but thing is.. If this is not an App it's not usable. People tend to listen this while resting (in bed for example) so makes no sense have this in browser. For example [0] stops playing when screen is off/locked
I'm testing a PWA version at the moment too so it'll be installable to your home screen - the test version at https://test.ambiph.one is PWA-enabled if anyone would like to try it out