There is no way to distinguish which one is which.
It is possible in SQL to join devices and positions table, so would it be feasible to put a "Name" column in the report, or perhaps to highlight the relevant row in the Devices pane when a position is selected on the map?
I would recommend to put your request on GitHub and we'll consider it for one of the future versions.
Hoping I am in the right thread... how to I see the trail that my unit traveled? I am only seeing a short red line as it moves. I was expecting a complete trail and I am suspecting that I have a setting wrong maybe?
If you want to see full history, you have to use reports.
When I run a "route" report for a group, the map shows lots of trails, but I cannot see how to get the device name for a particular trail so I know which vehicle it refers to.