I don't follow... Yes, the signaling *would* be actionable...
- In the case of the school / library -- certain networks and / or hostnames get you a captive portal notification (even if not HTTP) tell you about your limitations
- In the case of the network that doesn't allow HTTP and SMTP (or other protocols) you get a captive portal notification (even if not using HTTP)
- In the case of the lowered tier network ... The point here is that network doesn't NEED to have everyone go through the portal (or even both everyone with the portal before using the network)... The notification can come later, for instance, when the network starts dropping pkts because of the user's usage. How does a user change their mind, move to a new location and start over?