BillsBayou
Chumono
The last point is the third point in my criteria for cutting a high root. You may be able to ignore, or stretch the limits of the first two points, but if your trunk is noticeably fatter above a high root, you're stuck with it.Bill, I am confused about your response starting with, "that last point is a killer".
Assuming I am able to cut and remove the 1 or couple roots at the soil line now, I was planning to bare root the tree and pot it up in the same container (in April and if its strong), basically just switching the soil out and positioning the tree higher within the pot, where the main basal flare is just under the soil line.
If you're going to bare root the tree, you're going to have a narrow window somewhere in April. You want the new growth to be pronounced and you want Spring's buds in full leaf. But you don't want it too hot to do a bare root on a tree that you're pushing hard. The tree has been chopped and it's trying to recover, and you're repotting, and it's getting hot. So pray for cool weather in mid-April. I'd cut the roots to a depth of 5-inches and pot the tree into a mason tub with no holes. Keep it fulled drowned. To cut down on mosquitoes, I keep bottles of insecticidal oil all over my growing areas. I add a few drops here and there to keep those little bastards from breeding.
Note on insecticidal oils: They're petroleum based. If you have any buttonwoods (Conocarpus erectus), never spray them with any oil-based insecticide. It'll kill the tree.