It would be fantastic if sponsors for guest SSID access could be limited to a trusted group, whether this be via entering valid sponsor emails or linking via something like Active Directory.
Allowing anyone with a valid email address on a domain to approve guest SSID access essentially makes this feature useless for larger organisations where not every member of the domain is "trusted" to do so.
SSID access can already be limited in this way via AD integration, but this only works for members of the domain. Not guests to the network.