...
In order for SAML services to participate in SLO, the SAML metadata supplied for them must contain appropriate <SingleLogoutService> endpoints. If there are multiple endpoints that vary by location, the standard does not stipulate how an IdP is to determine which endpoint to use. In V4.2+, the The IdP will attempt to select the endpoint based on the best match possible between the logout endpoint and the original endpoint used to deliver the authentication response.
...