Interesting Ash

[Jesse]

The tree has now almost developed as two trees and the split has recovered well and developed substantial adaptive growth and developed new supportive roots, look at the base of the split and rather than it continuing down into the grown a new root collar has developed from the base of the split which must have produced adequate anchorage to support the tree as it is now. With the absence of any fruiting bodies or pathogens I would still say leave alone or go with Tonys recommendation, soil fill and pollard.