@gorv 

Hi, welcome to the community.

Generally speaking, the configuration process with Portal has no difference from the normal wireless network for RE305.

However, as the Portal authentication methods of public Wi-Fi are not uniform, we haven't done field testing, and we can not guarantee that it will work in all conditions.

Since you already have the RE305, you could try to set it up with the portal WiFi and check whether the mobile devices could get the redirect page for portal authentication when connecting to RE305.

Thank you very much and best regards.