So I just heard in a video that you can upgrade your regular free travel refillable mug to a skyliner metal mug for $10. Have any of you done this? Do you do it when you check in?
You can do it at the register at the quick service location where you first purchase and activate your mug. They are offered there. I will assume they are available only at those quick service restaurants at resorts served by the Skyliner. Hopefully others can confirm this assumption.