[Serusers] presence_b2b UA

Hello all. I have been experimenting with the ser-0.10.99-xxx branch(es) and have a question about the presence_b2b module. I realize that the module is not yet fully complete but according to the documentation, when finished, the module should be able to take an inbound SUBSCRIBE request and then create a new SUBSCRIBE request outbound to another SIP entity or multiple SIP entities, ie Asterisk servers, hence the back to back functionality. What is the status of this functionality? Is anyone currently working to complete this functionality? I would be interested in helping complete or sponsoring the completion of this functionality. My intent is to have a SER server act as the central watcher database server and have all SUBSCRIBE and NOTIFY requests channeled through this SER server. This SER server will then generate new SUBSCRIBE requests out to each server in a farm of Asterisk servers and the Asterisk servers will then send NOTIFIES back to the SER watcher server. The watcher server will then take care of sending the NOTIFY messages to the correct watcher(s), according to the data in its watcher database. Is anyone currently doing anything similar to this using a different method or is using the yet to be completed B2B UA the correct/only way to accomplish this? Thanks, -Curt