One thing that I
noticed since going to the "beads" for balancing, my tires are wearing very well, no cupping.
When you balance a tire with weights, the tire is balanced at that moment. As the tire wears, that balance is slightly changing. Over time and as the wear continues, you can often see cupping, like what yours is doing. Also, when the tire deflates a little, that will also change the wear and balance.
This is just my experience with putting numerous tires on the ST1300s that I ride/have ridden over the last 14 years.
I am not an tire engineer, nor mechanic by any means, these are just my observations!
You're experiences may vary!