Based on my experience, 67i firmware update from 8.50 to 8.80 changed the way the 67i handles incoming InReach message when in expedition mode. I'm still trying to clarify how it changed, but here's what I know as of 10/5/24:
Before the 8.80 update, if my 67i was in expedition mode, it received InReach messages fairly quickly. Less quickly than in what I'll call "full-power" mode, but usually within an hour or two. But receipt of the message would cause the 67i to exit expedition mode and remain in full-power mode. I complained to Garmin about this a few months ago because it could result in unexpected draining of the battery, which might be critical in circumstances where expedition mode is likely to be used. I tested my device again just prior to updating to 8.80 to reconfirm the problem.
I am still uncertain exactly what happens when a message is sent to a 67i in expedition mode, but I am fairly confident that the risk of unexpected battery drain was eliminated with the 8.80 firmware update. I believe my 67i now reliably remains in expedition mode even though messages have been sent to it. In two tests it stayed in expedition mode for 36 hours and 18 hours after messages had been sent to it.
What I'm uncertain about is (1) whether the 67i will receive messages at all when in expedition mode, and (2) if it does, whether it will display the double-green LED signal. In either case, that's less of a problem than the one I complained to Garmin about. I can still receive pending messages by CHOOSING to exit expedition mode. So there is no longer the risk of discovering a dead battery in circumstances where it's most critical. In one test that ended today, a message sent 10/5/24, 00:19 Z while my 67i was in expedition mode was not received until 10/5/25 18:15 Z after I manually exited from expedition mode.
I recall that before the 8.80 update, my 67i received messages while in expedition mode, displayed the double-green LED signal; and until version 8.50, remained in expedition mode after a message was received. I'm relying on memory for that observation since I cannot revert back to earlier firmware to check.
