I always dig and chop at the same time, regardless of species. If you chop a tree in the ground, the following year it will be weaker at collection time. If you collect a tree and chop the next year, it’ll struggle to push as many new buds. If you chop and dig at the same time, when the tree is at the peak of vigor for both operations, it must respond to pruning at both ends, so its resources are split. Overall, I don’t think there’s a wrong order of operations. I worry about (a) collecting enough roots and (b) providing good aftercare. When a collection fails, for me it’s almost always a tree with too little root mass. However, for a tree on the edge, you can tip the balance in the tree’s favor with warm spring temperatures, cool summer temperatures, and high all around humidity.