> And yet I am still tempted to add this 204 service, but maybe then I also don't have internet on my phone anymore because it keeps believing it's behind a cap

> And yet I am still tempted to add this 204 service, but maybe then I also don't have internet on my phone anymore because it keeps believing it's behind a captive portal when the service is offline Try it. Normally Android will say "This connection doesn't give you internet, connect anyway?" then you press yes, and everything works. (Except if you're on a captive portal, in which case you'll need to type example.com in your browser to access the captive portal).