Currently I'm using a Garmin 510 for my Bike Rides and the Fenix 3 for everything else.
I'm using the excellent ActiFace Watch face https://forums.garmin.com/showthread.php?213535-Watchface-ActiFace-FR920XT-Vivoactive-epix which displays activity based on Fenix 3 usage which is great.
As the garmin connect app is aware of my bike ride activities via the 510 (Or any other garmin device) it would seem very useful if the Connect IQ API allowed you to make a call to the App to find ALL activity vs Activity based on the watch alone.
This would allow the ActiFace watch face for example to show an accurate activity graph.
I know I could simply record the activity on both 510/Fenix3 but I would assume there are a few people with multiple garmin devices who would like to be able to access totals for all devices on their smart watch.