Keycloak logout before receiving SAML logoutResponse

We have been having problems with SAML SLO. Client that initiates SLO is not logged out, while other clients are. We noticed that this is because our IDP does not always send LogoutResponse to initiating client. We contacted our IDP and they instructed us, that we should logout our client before sending logoutRequest to them.

We are currently using Keycloak version 9.0.3. My questions are:
a) Is there a way to do this? I have searched, but not found any option for this anywhere.
b) Would that feature be against SAML specifications? If so, is it unlikely to get such feature ever implemented into keycloak?