Garmin Express Is Now At 18.104.22.168 (As Of November 16, 2017).
This was as of yesterday. As I had previously told you, Garmin Express (at least on Windows) does NOT auto-update or provide you with any notification that an update is available. You have to check manually.
Not sure what going up to 5.8 from 5.7 did. I haven’t seen any differences. Maybe it was to add support to the Vivoactive 3.