That's normal. The reason it shows 100% for such long time is because of it's eating the buffer, which is around 8% of total capacity. After that, it will start to eat the usable capacity....
If that soh is true, you should try to let your battery stay at 100% or 0% longer, so that you will have the soh droped below 70% sooner, and let Ford replace a new battery pack for you.
Thanks for sharing your experience.
Other then the tires and windshield, what maintenance/repairs have you done on your baby? The 97.5%SOH is pretty impressive considering the mileage. Did you charge to 90% daily? I saw your had a battery issues at 50k miles, did the dealership change any bettery?