Although with rather long delay, I started to work on it. First step was to add support for storing the record-route and contact values in the branch record (topos_t table). Can you test with latest master branch and see if those fields are set after 180/183? I didn't have time to do any tests yet by myself. If this part is ok, then I will continue to implement using them for routing PRACK and other requests during early dialog state.