@chad63e Hi Chad, @stucork has replied to my query and I think it works! 
Could you have a look at his reply and test with your setup too? I tried on mobile, and I am using Vivaldi and Opera and both are now receiving web push notifications even when the browsers are closed. Modify anvil http-headers to broaden the scope of service workers? - #3
I dont know how we could do it with the dependency, maybe one would have to manually upload the service worker JS script file, but that is just fine I am very inexperienced in these things, but I guess this is it Let’s roll