hi,
 
i did may tests with the "holger/subscr-ref-handling" branch. i had no subscriber usage leak within may hours of testing. about hunded calls were made with many out-of-range failures, hold/retrieve, and battery removal during call. at the end, all subscribers usage returned back to 0.
 
i did not test SMS, just location updates and voice calls.
 
regards,
 
andreas