daniel,
there is one more thing.
long time ago i added to ser parsing of Allow header and methods contact parameter. the idea was that if register request has methods contact parameter for a contact or Allow header for the request (the former takes precedence), new location/methods column of type unsigned int would be set accordingly. then it would be possible to select if it makes sense to send a request (such as SUBSCRIBE or REFER) to a particular contact or not.
the plan was that jan would write the location related part of this code, but it was forgotten and never happened. i still think that it would be useful to have this functionality and it would not be a big deal to add this to ul module. i would, however, prefer that someone more familiar with ul module would do it in order to avoid making mistakes.
so perhaps daniel could add this one to the list too.
-- juha