“I presume you mean gps 1.2 format for the 'Save as'? That is what I used for my XT.”
It’s the other way around as I believe you want to see the Shaping Points and the Via Points.
The .GPX 1.2 (Route,Track, POI) is the one that will only show the Via Points but does give the full route.
The .GPX 1.1 (Route,Track, POI) is the one that will show Via Points and Shaping Points.
Both will automatically create the route in the Garmin XT Trip Planner.