Hey team,
Started to use your app for building my plans, looks really cool.
But I faced some issues when I try to connect with my Garmin.
The first and foremost it’s completely not clear for me that instead of Send To Garmin I should sync Calendar.
What I did, I created a plan and sent to Garmin, changed date and sent again and I had a 2 pairs of every workouts in Garmin Calendar.
I think if we can educate the user “Are you sure you want to send it to Garmin, if you want to keep it up to date sync with Trainer Day Calendar and we’ll do it all for you”.
Okay, it wasn’t the end, I tried to clean up my calendar in Garmin and I couldn’t do it as they don’t support bulk deletes, I went with a way of deleting with a console script, but it didn’t work as it’s outdated, Garmin changed class names 
Eventually I found similar version script to yours fixed classNames and managed to delete workouts. You can find working code here: Update GARMIN_Bulk_Workout_Delete by vladimir-polyakov · Pull Request #1 · anthonws/Misc-Scripts · GitHub .
Seems like it worth to update the blog post to help people who suffered as I did.
Thanks, Vladimir