Hi,
It is ultimately your decision but I don’t see your plan working. This is because where you want to air-layer there’s a big knot of branches which won’t look very nice if you want a single trunk etc. My idea would be a bit out of the box. Air layer just under the big knot of branches and do a clump/multi trunk design. The other thinking would be to do an air layer half way and remove the knot etc.
These trees are so vigorous that you can chop it down to a few inches from the roots and it will throw heaps of new buds/branches/new trunk.
Anyway, thinks to think about etc.
Charles