There are several captive portal parameters one could apply to an Android device via
settings put global – the most famous probably being
settings put global captive_portal_detection_enabled 0
to completely turn off captive portal check (for Android < 8). Can someone explain how to use the others – e.g. to define a "custom captive portal server for tin-foils"? For example, one cannot simply do a
settings put global captive_portal_server example.com
as that would, in most cases, cause captive portal check to permanently fail (background: doing so, portal check would construct an URL
http://example.com/generate_204 and check against that, expecting a specific response).
So apart from simply deactivating captive portal check altogether (which might, as I've read, lead to other issues like not being redirected to the correct portal in some cases), what else can one do to enhance privacy in this context?
Examples (if I got them right):
0: Don't attempt to detect captive portals
1: Prompt the user to sign in
2: Immediately disconnect from the network and do not reconnect to that network in the future
0: Completely disable captive portal checks
1: Enable it (default)
While these examples are pretty much straight-forward: How to use the other parameters?