[SR-Users] Using static entries with usrloc

Hello, Normally I wouldn't be asking this but I was surprised to find no reference to anyone doing this online. I need to have a few AoRs with static entries in kami's location table, which will always be reachable at their contacts without ever having to register with Kamailio. Am I right in thinking that merely INSERTing respective rows in kamailio's location DB backend will do the trick? Is there anything I need to worry about, like contacts being periodically purged? If yes, how do I prevent that from happening? And will kamailio always query the DB when performing location lookup or do I need to restart upon inserting new records (to purge caches, for example)? Lastly, I'm not sure how to treat some fields present in usrloc tables like ruid, expires (can I set this to NULL?), callid and cseq (which is irrelevant since there's no REGISTER), flags, cflags and methods. Thanks, George