PicketLink IDP supports SAML2 SP-Initiated SSO and SAML 1.1 IDP-Initiated SSO. There is a requirement to support SAML2 IDP-Initiated SSO.
Right now, in the absence of SAML2 request/response, the IDP moves to a SAML 1.1 workflow as described in https://docs.jboss.org/author/display/PLINK/SAML+v1.1
A change would be to make it configurable at the IDP to use SAML2 IDP initiated workflow in the absence of SAML2 request/response payload.
https://issues.jboss.org/browse/PLINK-364
Available in 2.6.0.CR1 and later.
Targeted for PicketLink v2.6.0.Final