On the Inreach site under "plans and devices" tab there is an option to choose active collection. I select one and it doesn't seem to do anything to the device after sync. It seems this would only include one collection on your device, which would be a nice option I would use.
This feature is part of our updated interface for the Explore website. Collections provide a way for you to organize the data that has been recorded and synced from your inReach device. Setting an active collection allows you to automatically sort new data into a specific collection rather than having it all go into the library to be sorted later. There's a little more info on that in our Support Center at the link below: