Looks like Garmin finally solved their conceptual/coding issues with using segments while navigating. On a ride yesterday with navigation every (Garmin) segment did trigger and stopped after I crossed the finish line (this didn't work prior to 9.30).
Looks like Garmin is halting the existing navigation when a segment is triggered: The ETA time changes to ETA at segment finish and once the segment has been ridden I get an Off Course warning prior to the normal navigation being resumed.
I think this, mainly conceptual bug fixing, and the recent slowdown in updates for the Edge x30 series is a good indication of an incoming x40 series Edges.