[keycloak-user] Brokered logins only?

Any way (other than a custom theme that enforces it in the UI) to allow only brokered logins to a realm? For reasons beyond my control, the user's password is the same in the IDP as it is in KC (they point at the same OU in LDAP), but the IDP has been configured with a particular 2FA method that is not supported by KC. So the problem is that if the users login with username/password submission on the KC login page, they can bypass the IDP's 2FA. We can set the IDP as the default, but kc_idp_hint as a blank value will bring up the KC login page. Maybe there's a way to adjust the flows so that brokered login works, but username/password submission on the KC login page fails (or is not even offered)? Maybe setup pre-configured OTPs on the accounts, so that the users can't get past there? (this would be a bad, confusing UX) Any other ideas? Regards, Peter K. Boucher