Yes i'm using a 3rd party Sim. Sadly, i think so you are right RI_UC pin is not physically available otherwise i could have wired it.
So the question is is there a way we can specify two different pins as wakeUpPin in below function. That will allow for a local D2 pin interrupt and RI_UC interrupt for following;
iSystem.sleep(uint16_t wakeUpPin, uint16_t edgeTriggerMode, SLEEP_NETWORK_STANDBY, long seconds);
Or unless there is a way to assign RI_UC a physical pin through low level programming, that might also work.