Good first technique for pack usable capacity calculation, though you will get a more accurate value if you charge to full (top balance cells) and then drain to ~15% or less (if you feel comfortable). I do not think data from EVSE is reliable, considering unknown charging losses.
We’ll see if e-Golf pack refurbishment becomes a widespread business. I think there are already some shops that replace Leaf packs.
My car has 36,000 miles now and is holding steady around 28 to 30 kWh usable (varies a bit due to rounding errors in data I can get from car) in warm weather.
2017 e-Golf LE, Multi Coat White with Black Vegan Leather interior, purchased in early 2018
2015 e-Golf SEL leased for three years, returned in early 2018