The technique is definitely cool, but can it really be called "sustainable"?
I think I once heard that most trees that coppice or pollard well are adapted to beaver predation. We just make a cleaner cut than the beaver.
In other words, I think it's more like a luxury, and I won't call luxury items "sustainable".
So no real evidence.
> I won't call luxury items "sustainable"
How is wood a "luxury" item. Fruit and nut orchards both require significant man-hour and monetary effort, they would also be considered unsustainable luxuries using these rules.