I’ve had excellent success doing Bark grafts, somewhere around 90%. My failures were on bark grafts onto weaker trees where there was previously a failed cleft or side veneer graft.
If you bark graft, you don’t have to wait for new shoots and if your bark graft fails, your tree should send out new shoots behind where the cut was made.
Recently, I’ve made a slight alteration to the normal bark graft that wraps the scion better and seems to promote better healing and aesthetics of the bark graft. I’ll share the technique in another thread when I get some more time.
Simon