it will append that information as part of the redirect, but in either the RADIUS server settings or captive portal profile settings you can opt to have some of that information included in the redirect or not.
The user connects to guest, tries to browse to a page and gets redirected, but the page displays "too many redirects". What path is the guest traffic taking, is it going outside the network, then back in through a NAT on a firewall or is it staying internal the whole time?
Are you using any kind of landing pages for time-based or device-based redirection besides the normal registration / login page?