I have 3 pairs of shoes: 1 for Road and 2 for trail.
In Gear/Automatically Add to... there are only 6 default activities you can assign shoes to (whereas the watch has a lot more activities)
This is extremely silly and annoying since I have to manually edit each trail run to change the gear so I can track the shoe.
Seems like a 10 minute R&D task but this bad UX is the same for years.
What's up with that Garmin?! 
Why is it so hard to make the "assign gear to" list reflect the activity list on the watch (or at least the favorites)?