Can you start an air layer over a cut branch?

[Cruiser]

Is it feasible to girdle a stem over a cut branch when starting an air layer? If so, how might it affect root growth at that location?

Context: A large vine maple I’d like to air layer above its graft. There are low branches in the way that are 1/3-1/2” diameter.

 

[Wires_Guy_wires]

I'd say there are two possibilities: rot or roots.
Either the wound is too large and it will not heal in time, leaving an open wound while the rest sends out roots.. Or the wound produces its own roots.
Maybe it's wise to cut the branches and let them heal over before you do the air layer. That would be the safest option.

 

[Shibui]

Roots will come from exposed cambium. If the girdle crosses a branch scar the roots should form along the exposed cambium. Depending how big the cut is and what is included in the layer you may get roots higher if the branch cut is higher than the rest of the girdle but still included in the layer.
If the top of the branch cut is exposed above the layer no roots can form across the cut so there will be a gap in the root layer there.
If you make the girdle wide enough or high enough to have the top cut level with the top of any branch cuts there should be no problem.