Is it possible to force SBC to check the P-Associated-URIs during the Findregistry procedure?

Hello,

I have one PBX which is connected to SBC as a peer. There is surrogate-agent configured for this PBX that registers pilot number 0123030 on a registrar. Registrar sends 200OK with several P-Associated-URIs. From Registrar's perspective, the numbers in P-Associated-URI are "child" numbers (0123031-0123039) which belong to the pilot 0123030. Those nine child numbers are the extensions on PBX. I see that when any of child numbers try to make an outgoing call, SBC routes the call to I-CSCF and not apply the Service-Route, recorded in the cache for pilot registration.