I asked the same question before and didn't get any answser:
Looking at the source code, Wildfly Elytron OIDC Client only uses the URL path in the redirect_uri query parameter
when redirecting to Keycloak in an authentication flow. It completely ignores the query paramaters of the secured URL
that the user is accessing. So Keycloak server has no information about these parameters.
Probably including these query parameters would break the URL parsing in the keycloak side.